


Barry Bluejeans and Where Loyalties Lie

by onArete



Series: The Most Powerfully Magic Number [6]
Category: Harry Potter - J. K. Rowling, The Adventure Zone (Podcast)
Genre: F/F, F/M, Harry Potter AU, Hogwarts, Hufflepuff, M/M, Order of the Phoenix (Harry Potter), Other, Starblaster - Freeform, Year 6, character death but it's stolen century so it's not permanent, half blood prince, light of creation
Language: English
Status: Completed
Published: 2019-06-28
Updated: 2019-09-13
Packaged: 2020-05-28 12:26:38
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 11
Words: 25,096
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19394125
Author URL: https://archiveofourown.org/users/onArete/pseuds/onArete
Summary: The crew of the Starblaster has been attending Hogwarts for the past five years.  Going into sixth year, Barry isn't too nervous.  They've infiltrated the Death Eaters and Dumbledore's Army, passed all their exams, and managed to keep everybody alive.But nothing is ever as easy as it seems.  And sixth year might just be the most difficult one yet.





	1. Algorithm: a step by step procedure by which an operation may be carried out

**Author's Note:**

> Hey everybody!!!!!! Welcome to sixth year! I would HIGHLY recommend reading the other books in this series before this one. Updates on Fridays!

Sixth year began with a big, Hufflepuff meeting, as all years did. 

“Good work, everybody,” said the seventh year prefect, a tall girl named Sofia. “You made it this far! To the new first years-- welcome to Hufflepuff! Your second year buddies have already been assigned, and they’ll come find you once we’re done with this house meeting and show you the ropes. To the rest of you-- welcome back! Hufflepuff may get a bad rep, but we’re the house of the loyal and the patient and the hardworking. We can do _anything_ we put our minds to.

“Some kinda crazy stuff’s been going on lately,” Sofia continued. Merle sneezed and maybe-accidentally elbowed Barry in the ribs. The couch they’d squeezed onto was very crowded, but it was because they were sixth years they get a couch at all. Barry had felt bad about taking the cough, a little bit, but Merle had tugged him down. “A couple years ago, we had the Triwizard Tournament. Most of you know that we lost the Hogwarts Champion and Hufflepuff, Cedric Diggory.” A moment of silence spread over the room, but Sofia quickly broke it. “Last year, at the end of the school year, He-Who-Must-Not-Be-Named returned. If you haven’t seen the safety pamphlet ‘Protecting Yourself and Your Loved Ones’--” she held up a purple pamphlet from a stack on a table-- “Grab one from me. But! We are gonna have a _bloody good year_.”

Some fourth year raised his hand. Sofia pointed at him. “Jerry?”

“Who’s the new guy who looks like a walrus?” Jerry had a slight lisp, but Barry knew _exactly_ who he was talking about. The new professor, sitting up at the professors table. He’d been too busy reviewing his notes on one of his arithmancy projects he’d been working on over the summer to go over with Professor Vector, and completely spaced on his introduction. Apparently Jerry had as well.

“That would be Professor Horace Slughorn. He’s teaching potions.”

A surprised murmur rippled through the common room. Somebody shouted out, “What happened to Snape?”

Somebody else yelled, “Did he die?”

And another-- “Oh boy do I hope he--”

“Professor Snape is not dead,” Sofia shouted, and the crowd quieted. 

“Unfortunately,” Merle muttered under his breath. Barry snorted. Sofia shot him a look.

“Snape will be taking over Defense Against the Dark Arts,” Sofia continued. A roar of noise-- “And! If you are a fifth year or below, you _cannot_ drop the class. Sorry.”

“Ugh,” said a tiny second year.

“Maybe the curse’ll get ‘im!” said Jerry.

“Please talk after I’m done,” said Sofia. The room quieted quickly. They were just kids, but they were pretty good kids, too. “This is gonna be a _good year_. Sixth years will meet tomorrow morning with Professor Sprout to discuss their new schedules. Everybody else should’ve gotten theirs at dinner. Lights out at ten for third years and below, midnight for everybody else. We’ve got snacks and drinks--” she pointed across the room at a fridge, and a small chorus of whoops started up-- “So enjoy your year! Classes start tomorrow! Thank you!”

“Thank you Sofia!” somebody shouted back, and everybody started clapping. Barry laughed, and clapped along. Nudged Merle until he clapped, too.

\---

“So, Barry,” said Professor Sprout in her round voice like a copper kettle when Barry met with her the next morning after breakfast. She shuffled a couple pieces of paper in front of her on the plant-covered desk, adjusted her glasses. Barry crossed his arms, and then uncrossed them. Crossed them again. “Looks like you passed everything you took. O’s in Arithmancy and Ancient Runes, E’s in Transfiguration, Charms, Herbology, and Defense Against the Dark Arts, A’s in Potions, Divination, and Astronomy. Well _done_!”

“Uh, thanks,” said Barry.

Sprout nodded. “In your interview with me last year, you said you wanted to pursue a career in expanding magic through Arithmancy. Is that still your plan?”

“Yeah,” Barry said. It would be the plan, if he was gonna stay on this plane past seventh year. “Yeah, that’s what I’m gonna do.”

“Excellent! It’s not a career for which you need specific classes and courses-- other than Arithmancy, of course. I’d also suggest remaining in Charms, Transfiguration, and Defense Against the Dark Arts, just to keep up on your current magic abilities. Potions can be a handy everyday skill, and if you talk to Professor Slughorn, I’m sure he’d let you in with an A. And I would love to see you continue in Herbology.”

“How many classes do I _have_ to take?”

“A minimum of four, but we _officially_ recommend five or more--”

“I’m just gonna, uh, do Arithmancy and Charms and Transfiguration and DADA like you said.”

“Are you sure? You’re very bright, Barry, do you want to only do those--?”

“I’m sure.” He nodded. He couldn’t tell Sprout, of course, but knowing how to do Divination or memorizing this plane’s solar system wouldn’t have any sort of effect on him once the seven years on Cycle 70 were up. “Yeah, bud, I don’t think I’m really gonna need Divination or whatever.”

Sprout looked _very_ confused. “ _Bud_?” she muttered, and then cleared her throat. “If you’re sure that’s what you want to do, that will be good. You won’t need your time turner this year, then. You still have it?”

Yeah, Barry had it. But he’d lived with the twins for far too long to give up any advantage that he had at all. “Uh... no. Sorry.”

“What happened to it?”

“I, uh... I returned it to Dumbledore last year,” Barry lied. “He said he’d taken it back to the Ministry. And didn’t they all get destroyed during the, uh, invasion?”

A pause, a moment so long it got awkward. Barry tried to resist the urge to polish his glasses. Then he took off his glasses, and polished them on the sleeve of his robe.

When he put them on again and the world fell into sharp focus, Professor Sprout pushed a piece of parchment across the table to him. “Here’s your schedule, then. You’ve been doing independent studies with Professor Vector, yes? Wonderful! You’ll have to schedule those with her, but they should fit in nicely. You’re going to do great things, Barry.”

“Uh, thank you,” he said, standing and pocketing his schedule. Turned to leave.

“Oh, one more thing,” said Professor Sprout, glancing almost suspiciously over his shoulder, lowering her voice. “You were at the Ministry last year when You Know Who attacked. Would you be interested in, perhaps, doing more to... help out in that effort?”

“I’ve already got the pamphlet,” Barry said. “Sofia handed them out yesterday.”

A smile crossed Sprout’s lined face. “She’s a good girl. But I meant something a little more hands on, Barry.”

He sat back down in the chair. This had gone much beyond a class schedule, but he’d be lying if he said that it wasn’t a little bit thrilling. There was a reason he’d joined the IPRE, a reason he was selected for the Starblaster mission back home on Tosun V. And a lot of it was that he was a great arcanist and scientist. But he also liked to _find_ things. To _discover_ . To _do_ things, as much as he could.

Barry had been an interplanar adventurer for seventy-five years. He’d been a forced student for five of those. And he was almost aching to get a little more excitement.

“I’d be interested,” he said, absently pulling his wand out of his robes and fiddling with it. “What exactly are you talking?”

“I can’t tell you anything more,” Sprout said. “I wish I could. You’ll need to talk to Professor McGonagall. But you have my recommendation, Barry, although I don’t think you’ll need it.”

Recommendation?

“Is this, like... a college?”

Sprout just laughed. “Not quite. But you’ll have my recommendation for that, too, if you pursue that after Hogwarts.”

“Uh, thanks, I guess.” Barry stood. “I’ll see you in Herb-- huh. Guess I’ll just see you at meals.”

Sprout nodded, once, and a brief flash of exhaustion crossed her face before it was covered with her customary smile. And she waved goodbye as he left her office.

\---

The Defense Against the Dark Arts class was _tiny_ . Sure, it was only Hufflepuff and Ravenclaw paired together, but it was just so small. He managed to snag a seat next to Padma Patil, a Ravenclaw girl who had been part of Dumbledore’s Army the previous year. Lucretia and Davenport sat together near the back, in a small group of the sixth years who took DADA and who quietly supported Voldemort. Or in Davenport’s case, were pretending to support him. Or in Lucretia’s case, were staying _firmly_ neutral. So neutral that she couldn’t sit near Barry because he’d been at the Ministry the year before.

But Padma was great. Still, he wished Merle had sucked it up and taken DADA. But the minute he’d found out that Snape was teaching, he’s shrugged, and said, “He can kiss my _ass_.”

Snape hadn’t arrived yet, though. A quiet murmur of chatter swam across the classroom, as students talked about their summers and new class schedules, books and wands and quills all ready to go on their desks.

“How was your summer, Barry?” asked Padma, adjusting her book on her desk.

“Pretty good,” he said, pushing his bag under his chair. “Yours?”

She shrugged. “Me ‘n Parvati spent a month in India with our grandparents. It’s always the coming back to school that’s the worst.”

“Oh yeah,” he said. “You get so _used_ to the freedom and--”

“Exactly--!”

_BANG_!

The door flew open and crashed against the wall. The room fell silent instantly, Barry and Padma’s conversation dropping to nothing.

Snape breezed into the room oozing with style and panache. Barry could admire that. He reminded him of the twins, if they were super goth and also had never heard of shampoo. But his spiels at the beginning of every school year had gotten a little old. So he tuned him out with the polite expression he used to use at the IPRE after all-nighters, and sat quietly as Snape explained how Defense Against the Dark Arts had changed.

More talking about the _actual_ Dark Arts they would encounter. That, Barry figured, would be useful. And even though Snape looked like he’d always just been sucking on a lemon, he was a good enough teacher.

But thank the gods Barry wasn’t a Gryffindor. He didn’t think he’d be able to stand how pissy Snape was to them.

At least nonverbal spells sounded like they’d be useful.

\---

“Ya comin’?” asked Merle that Thursday night, standing in the door of the dorm room the Hufflepuff sixth year boys shared.

Barry looked up from his desk and his half-complete Arithmancy proof. “What?”

“It’s Thursday! Family meetin’ time!”

“Oh, shit, yeah.” He quickly capped his inkwell, and shoved his chair away from the desk. “We’re still doing that?”

“No shit! We’re still a family, aren’t we?”

“I mean, yeah-- but after the Ministry and all, last year--”

Merle laughed. “Ministry, _Schministry_. That doesn’t change nothin’. C’mon!”

Barry followed Merle out into the Hufflepuff common room, waved at the people in there-- Sofia, fifth year Arnulf, little first year Jessie-- and stepped into the private meeting room. A quick glance around told him that everybody was there, so he shut the door behind him, and flipped the lock.

“Glad to have everybody here,” said Davenport, nodding at Barry as he took his seat. “Everybody settling in okay?”

Murmurs off assent.

“Draco’s going batshit,” Taako said, not looking at the others, busily tossing his wand into the air so it would spin and then catching it as it fell back down. “Something about Potter tracking him on the train.”

“So?” asked Magnus. “He’s _always_ batshit.”

“He’s _also_ an official Death Eater now,” Taako retorted.

“A what?” asked Merle, breaking the tension with cluelessness that Barry was kind of grateful for.

“A Death Eater, try to keep up.” Throw the wand, spin, and catch. “He’s got the Mark and everything.”

“How do _you_ know this?” asked Lup, leaning forward with her elbows on the table. “Doesn’t seem like the kinda thing he’d just go around showing off.”

“I’m _getting_ there,” Taako retorted, tone closer to bickering than actual arguing. “ _So_ . Draco’s dad fucked up _royally_ at the Ministry last year--”

“Awwww, was that a _compliment_?” said Lup, draping herself across Taako’s shoulders. “From my babiest brother?”

“I’m older, fuck you,” he responded immediately. “Anyway, Funguspants--”

“Who?” asked Barry.

“Voldemort. Moldyshorts. Funguspants. Please try to keep up, Barold.” Barry gave Taako a thumbs up. “Anyway, he’s making Draco try to kill Dumbledore.”

“ _What_?” said Lucretia, aghast. Her double-writing hands falling still for a brief moment.

“Yeah,” said Taako. “So, he’s gotta kill Dumbledore. Asked our whole band of Death Eater wannabes to help out.”

“And you said yes, right?” asked Davenport.

“Of _course_ I did,” said Taako, almost offended. “Taako’s not a hack. I know how to play a long con.”

“I know,” said Davenport. “Just double-checking.”

“So... what now?” asked Lup.

They all sort of shrugged.

“We just keep doing what we’re doing?” offered Barry. Lup squeezed his hand.

A moment of silence. 

“Lup, didn’t you grab one of those prophecies?” asked Lucretia, out of the blue, the scritch-scratch of her double quills halting for just a second.

“Oh, yeah! Thanks for reminding me, babe!” she exclaimed, turning around and digging into her bag, eventually pulling out a small and dusky orb. “Addressed to all of us, yeah? If _somebodies_ \--” she glared very pointedly at Taako and Davenport-- “Hadn’t spent all summer making connections and shit, we’d’ve listened to it by now.”

Davenport rolled his eyes, slight enough that Barry could barely tell. He smiled.

“Let’s hear it, then,” said their captain.

“Everybody’s gotta touch it,” said Lup, placing it on the middle of the table. They all stood and reached, squeezing arms together awkwardly, bent at odd angles, so that everybody could get a finger on it.

The room went dark.

And a billowing, echoing voice reverberated from the prophecy crystal, filling them up from the inside out.

**“I SAW SEVEN BIRDS. I SAW THESE BIRDS ON AN EPIC JOURNEY, FOLLOWING A BRILLIANT AND BLINDING LIGHT. I SAW THIS LIGHT LAND IN OUR HOME, AND THE BIRDS FOLLOW. THEY HID IN BOTH THE DARKNESS AND THE LIGHT.**

**“BOTH DARK AND LIGHT SOUGHT TO STEAL THE LIGHT THEY HELD, BUT THEY DID NOT FALTER. I SAW SEVEN BIRDS BAND TOGETHER TO PROTECT OUR HOME. I SAW SEVEN BIRDS** **_TURN THE TIDE_ ** **.**

**“I. SAW. SEVEN. BIRDS.”**

Barry blinked and the darkness vanished, leaving just the words of the prophecy ringing through his head.

“Well,” said Magnus, cheerful. “What the fuck does _that_ mean?”

\---


	2. Element: a member of a set

**Summary for the Chapter:**

> The Order of the Phoenix (Junior!) assembles. Also, time turners, secret handshakes, and the animal language.

After his Transfiguration class, Barry hung back when McGonagall dismissed them. Sixth year Transfiguration was about as small as Defense Against the Dark Arts had been. Everybody had begun to specialize in classes for their future career. After five years of forty-odd people in a class, it was... strange. But a good sort of strange.

“Mister Bluejeans,” said McGonagall, as the last stragglers exited the room. “Can I help you with something?”

“Uh, yeah,” he said, adjusting the strap of his bookbag. “Professor Sprout sent me here. She mentioned, uh... doing more stuff like we did at the Ministry last year.”

Professor McGonagall levelled him a stare over the top of her glasses. “And would you?”

“Would I... what?”

“Be interested in doing more things of that sort?”

“Yeah,” said Barry. “Yeah, of course.”

“Have a seat, Mister Bluejeans.”

Barry did.

“It would be fairly similar to what Dumbledore’s Army was last year, but composed of only students in fifth, sixth, and seventh years, for safety reasons. You would be learning more defensive fighting from myself and the other heads of the houses.”

“Who’s invited to this... club?” Barry asked. “Besides the, uh, age requirements?”

“The students who are loyal to Hogwarts and to Headmaster Dumbledore.”

“So, like, Lup, Magnus...”

“You can assume that everybody who was at the Ministry last year will have been extended an invitation.”

“What about Slytherins?”

“If they are loyal, then they will be invited.”

He shuffled slightly awkwardly in his seat. This was a great opportunity-- a chance for him and most the rest of the crew to get in closer with Dumbledore and his people. But he couldn’t help but feel like it was a betrayal of Lucretia and Taako.

“Sounds great,” Barry said, and it felt as though a giant fist was tightening around his heart. “What’s the, uh, the name of this club?”

McGonagall straightened her glasses. “The Order of the Phoenix. You may have heard of it in your History of Magic classes.”

“Uh... I could use a refresher, I think.” Because he couldn’t remember the last time he’d  _ paid attention  _ in Binns’ History of Magic class. There were always so many more interesting things to do! Experiments to run, Jorts the owl to feed, adventures to find with Lup...  _ much  _ more interesting than sitting around class.

“The Order of the Phoenix was founded during the last great wizarding war, about twenty years ago, when You Know Who first came to power. The branch we are founding here is technically the Order of the Phoenix,  _ Junior _ .”

Barry snorted, then raised his hands to cover his mouth. “Uh, sorry-- sorry, Professor.”

McGonagall held her stern facade, and then a small smile crept onto her own face. “No apology needed, Mister Bluejeans. It is a bit of a silly name. As a matter of fact--” she glanced towards the door, and Barry followed her gaze, finding it closed-- “As you and your companions are techncially of age, any of you who so choose would be welcome among the  _ actual  _ Order of the Phoenix.”

“Oh. Thanks?”

She nodded, curt. “You’re welcome. But I must ask.  _ Why _ are Misters Yuno-fromtivi and Davenport-- as well as Miss Director-- choosing to not join with the rest of your companions in joining the winning side?”

“Uhh...”

How much did Barry trust Professor McGonagall? He respected her, absolutely. She was one of the three people-- the others being Dumbledore and Snape-- who knew the truth of the crew of the Starblaster and what they were actually doing at Hogwarts. But did he trust her with  _ this _ ?

“They’re, uh, like... spies. Playing the dark side, I guess?”

“Hmm,” said McGonnagall, with a small nod. “Thank you. I’ll keep that in mind.”

“So, when does this Order thingy start?”

“We’ll have our first meeting tomorrow evening, if you are available.”

“Uh, yeah. I think I am. Where?”

“You met in the Room of Requirement last year, with Dumbledore’s Army, yes?” Barry nodded. “There’s no need for that this year. We’ll meet in my classroom.”

“Cool.” Barry scooted out of his chair. “And, uh, thanks!”

\---

“So are you going to McGonagall’s thing today?” he asked Lup the next morning at breakfast, the two of them sitting side by side at the Hufflepuff table, Lup eating Barry’s eggs, even though there was a bowl full of them sitting in the middle of the table.

“Uh-huh,” she said, through a full mouthful. Swallowed. “Yep. You going, Bear?”

He shrugged. “Figured I would. Can’t hurt, right?”

“Magnus isn’t coming,” Lup told him.

“What? Why not? I figured he’d’ve been first in line for it.”

“Something about not trusting Dumbledore.” She took another bite of Barry’s eggs. “Stick it to the man, amiright?”

“McGonagall was, uh, was wondering why Dav and Taako and Creesh weren’t joining. Dunno what she’ll think of this.”

Lup shrugged. “I don’t give a fuck.”

Barry couldn’t help but smile. “Yeah, that’s what I figured. So just us and Merle, huh?”

“Oh boy,” she said, with a grin so bright he didn’t know how to look away. “That sounds like a  _ really  _ bad chaperoned date.”

Barry laughed, taking a swig of pumpkin juice. “So it’s a date, then, huh?”

“Oooh, sneaky,” said Lup, appreciative, and kissed his cheek. “I knew I liked you for a reason, Bluejeans.”

\---

“Can I help you, Mister Bluejeans?” asked Madam Pince, the librarian, shooting him a suspicious look over her spectacles. She’d been wary around him every since the research session where Lup had ended up on the ceiling, stuck there, and they couldn’t figure out the counterspell for four hours.

“Yeah, uh, I’m looking for stuff about the Order of the Phoenix. Uh, newspaper articles, books... anything, really.”

“Is this for class?” Pince asked, squinting at him.

“Uh.... yes?”

“Binns hasn’t given a recent history project for the past four decades.”

“It’s... extra credit?”

“I--”

Madam Pince was interrupted by another voice. “He’s alright, Madam Pince.”

Barry and Pince both turned to see Lucretia, walking into the library, tucking a book into her satchel. “I’ll vouch for him,” she continued. “I promise, he’s a lot less chaos on his own.”

Pince nodded curtly at Barry, and slightly less curtly at Lucretia. “I’ll go look through our newspaper archives.”

“Thank you,” he said to her retreating form, and then turned to Lucretia. “Whoof. Thanks for that.”

Lucretia laughed a little. “Yeah, no problem. Gods help me if she finds out I’m dating Lup too-- I don’t think she could handle that much chaos.”

Barry shook his head. “Yeah, no way. So, uh, how’re you doin’? It’s been a bit.”

“Pretty good,” she said, eyes wide and honest. “My group’s doing well. Everybody’s getting a little antsy, with You Know Who back, but... we’re good. We’re good.”

“That’s good.”

“God, we need some new adjectives.”

They broke into half-muffled laughter, and only stopped when Madam Pince arrived once more, carrying a small stack of newspapers in her arms.

“These are the Daily Prophets that mention the Order of the Phoenix,” she said, thumping them down in front of Barry. “They can’t leave the library. Return them to me or Miss Director here before you leave, got it?”

He nodded. “Uh, do you have other publications?”

“I’ll go check for you,” said Lucretia.

“Thank you, Miss Director,” said Madam Pince, as she disappeared into the maze of towering bookshelves.

Barry carefully picked up the stack of newspapers, and ignored the glare that Pince was giving him as he walked around a bookshelf and found an empty table. The nearby table, filled with a gaggle of second years from all houses shot him a suspicious look, quickly tucking something away.

Eh. He didn’t care that some kids had contraband in the library. Barry wasn’t a snitch. 

He picked up the first newspaper and flipped it open, found an article entitled, “What is the ‘Order of the Phoenix’?” and started to read.

Three hours later-- thank god for his spread-out schedule, or else he absolutely would’ve missed some class or another-- Barry had finished reading through the pile of Daily Prophets. But Lucretia had dropped off a handful of other publications: the Quibbler, Witch Weekly, a couple of foreign magazines.

Well, he had a couple more hours before he had to get to Charms. And this research to see what the Order of the Phoenix actually  _ was _ \-- before he and Lup and Merle went and got themselves entrenched in it-- was absolutely worth the time.

Barry rubbed his eyes-- jumped at an explosion from the other table, where the second years were playing Exploding Snap-- and grabbed the Quibbler. Started to read.

The various sources disagreed, to an extent, on what the Order of the Phoenix was. They couldn’t decide on any definite members except for Dumbledore-- and, of course, Lily and James Potter-- although Witch Weekly speculated that all the Hogwarts staff were in on it, and the Quibbler insisted that Dumbledore was the  _ only  _ member and simply duplicated himself for every battle. But mostly, they agreed that Dumbledore led the Order of the Phoenix and that it was composed of wizards, witches, and wixes who were loyal to him and trying to actively stop Voldemort’s rise. The obituaries were helpful, too-- placing the Prewett brothers as deceased Order members, along with Alice and Frank Longbottom, Emmeline Vance, and Marlene McKinnon. The story went that they were formed as a grassroots resistance group, and as the Ministry got corrupted, the Order of the Phoenix fought back.

They were set to lose the war until Voldemort targeted Lily and James Potter, seemingly without a good reason. But he couldn’t kill baby Harry Potter, and he died-- or, that’s what the old newspapers claimed. Barry knew better.

But the Order of the Phoenix... checked out. Even though the newspapers disagreed on it’s exact nature, for the most part, the narrative was consistent and coherent. He gathered up the newspapers and stacked them up, stood. Madam Pince swooped around the corner, already yelling at the second years, and Barry skirted past them, very glad he wasn’t the one getting the lecture.

He dropped the stack of newspapers and magazines onto Madam Pince’s desk, and checked the time.

Aw, shitballs.

He was late for Charms.

Glancing around the library entryway-- empty, perfect-- Barry pulled his time turner from under his robes, and spun it once. All around him the world twisted and spun, and he emerged in time, one hour previous. He could make it to Charms on time if he hurried.

He tucked the time turner away, shouldered his bag, and rushed out of the library.

\---

Barry and Merle were only a couple of minutes late to the Order of the Phoenix (Junior!) meeting, and it was all Merle’s fault. The dwarf had insisted on watering every plant in the Common room (an impressive one hundred and thirteen), and then double-checking the watering job on all the succulents. It was, according to Merle, a “ _ very  _ complicated process.”

Barry knew better, but after seventy-five years of trying to drag Merle away from his plants, he’d seen  _ way  _ too much. So really it was worth being late.

McGonagall stood at the head of her classroom. The first few rows were sprinkled with students that Barry recognized. Almost all of them had been at the Ministry last spring with them.

Luna Lovegood, Ginny Weasely. Rom Weasley, Harry Potter, Hermione Granger. Neville Longbottom and Katie Bell, Sofia Edgewood-- hell yeah, Sofia!-- Cho Chang, and Arihi Tran. Lup. A pretty good group, he figured. Even though, on the second glance around, there actually weren’t any Slytherins.

“Misters Bluejeans and Highchurch,” said McGonagall, voice crisp. “How nice of you to join us.”

Lup patted the empty seat next to her, and Barry sank into it. Merle settled down across the aisle next to Sofia, and they very quickly did the Hufflepuff handshake. 

It really wasn’t that quick.

Everybody sat in slightly awkward silence for about a minute while they bumped fists and slapped palms and knocked elbows and--

“May we begin now?” asked McGonagall.

They finished the handshake with a dab.

“Yeah, thanks for waiting,” said Sofia with a smile.

McGonagall nodded. “Welcome, all of you, to the first meeting of the Order of the Phoenix-- Junior.”

Lup snorted when she said “Junior,” and very quickly turned it into a cough. But sitting next to her, Barry could tell she was desperately hiding giggles behind her hand.

“You are all here because you have expressed and  _ demonstrated  _ your interest in contributing to the downfall of He Who Must Not Be Named,” McGonagall continued. “If that is contrary to anybody’s wishes here, now is the time to leave. There will be no judgement for that decision.”

An awkward moment ensued where everybody stared around the classroom at everybody else. But nobody spoke. And nobody left.

“Wonderful,” said McGonagall, voice crisp. “The official head of this organization is Headmaster Dumbledore, but I will be conducting most meetings. We will be a strictly non-combative group.”

“Could we be?” asked Ginny Weasely, hopeful.

McGonagall shot her a  _ look _ . To her credit, she didn’t seem to react. “No.”

“Boo.”

“As I was  _ saying _ ,” McGonagall continued, “We are strictly non-combative. The purpose of the Order of the Phoenix, Junior--” Lup started laughing again, buried her head in Barry’s shoulder-- “is to learn defensive and offensive spells. In the off chance that this current conflict is still continuing as you graduate, you will be more prepared to defend yourself and those around you.”

Lup’s laughs petered off, and she leaned up against Barry, and whispered in his ear, “Notice how that’s a good reason but she’s only teaching it to kids that she knows won’t use it against her, yeah?”

Barry nodded, and whispered back-- in the animal language they’d learned that first year, because it really never hurt to be  _ too  _ careful-- “Yeah. Uh, a safety net for them.”

Lup nodded, and McGonagall shot them a look, and they slid very slightly apart, hands finding each other in between their seats. And as McGongall began to outline something that seemed very much like a syllabus for a class that was all about fighting with magic-- something that they’d had seventy-odd years to perfect-- Lup squeezed Barry’s hand. He squeezed back. They were together. And they could face  _ anything  _ side by side.

\---


	3. Derivative: a measure of how a curve changes

**Summary for the Chapter:**

> Bond magic and... math? Also, good good goofs, a trip to Hogsmeade, and the beginnings of a new mystery.

“So the theory of bonds,” Barry said, “Is that everything that exists in this plane-- uh, world-- is connected. A teaspoon has a bond to the drawer it’s kept in. A wand has a bond to its rightful user. Uh, people have bonds, too-- I have a bond with my wife--  _ girlfriend _ , girlfriend I mean-- and I’ve got bonds with all my friends and--”

“Barry,” said Professor Vector gently. “I thought you were telling me about your summer research?”

“I am! Sorry, uh, I’m rambling.”

“A little, yes.” Vector smiled a little and took a sip of her tea. She and Barry had been working together with magical Arithmancy for the past six years, and their relationship had gotten much more casual. He’d help her grade papers. She would ask him to look over her latest theories. She was a sounding board for his Starblaster-related projects, and an excellent source of knowledge and ideas of how to connect these projects to the strange brand of magic that belonged to this Plane of Magic.

The only issue with his relationship with Vector was that she didn’t know Barry was an alien. So it made talking about things he’d already used and proved-- like bond magic-- kinda tricky.

“Bonds connect everything in the planarverse,” Barry said after a moment, trying to figure out how to best explain it. “And if you can manipulate them, you can manipulate almost anything.”

“So are these bonds tangible?” asked Vector. “Or theoretical?”

“Uhh... they’re proved,” he said slowly. The Starblaster’s bond engine did run on tangible bonds but Barry could think of a hundred million other things he’d rather do than explain the Starblaster and their past seventy-six year journey to Vector. Like get an ear infection because he went swimming without ear plugs. Or eat like, a metric  _ ton  _ of cheese. Or ice cream. Or yogurt. “I, uh, here’s that.”

Barry pulled a huge sheaf of paper from his book bag, very  _ very  _ grateful that he’d gotten that one extension spell whose name he could never remember put on it. It really made life carrying around armloads of paper easier.

He dropped the stack onto Vector’s desk. It was so tall that all he could see of her was her eyebrows as they raised.

“This is... a lot,” she said, after a moment, reaching around the stack of proofs and shifting it to the side so she could see Barry again. “You must have been very busy over the summer.”

He nodded somewhat uncomfortably, thinking back to the summer.

He’d spent a good portion of it hanging out with Lup and Lucretia on a road trip in a car they rented and maybe definitely  _ not  _ charmed the salesperson into giving them without having any sort of license whatsoever. Thankfully, the salesperson hadn’t commented on the gold pieces they used to pay for the car.

They’d driven across countries (and at one memorable point, levitated the car across an ocean) on a grand tour of Every Terrible Fast Food Place on the plane. Lup discovered a secret love for shitty greasy fries. Lucretia tried every grasshopper shake and when the summer ended, informed them that none of them had had actual insects in them. 

(“ _ What _ ?!” Lup screeched when she found out. “I could’ve been eating  _ not-bug milkshakes  _ all  _ summer  _ and I  _ wasn’t _ ?”

“You can have what’s left of mine,” Lucretia offered, trying not to laugh. Barry, driving, was already laughing. 

“Fine,” Lup said, taking the cup from Lucretia. And then she screamed.

And Barry and Lucretia lost their entire  _ shit _ . Live grasshoppers in a shake cup had been such a fucking  _ good idea _ .)

“Uh... yeah,” Barry said, realizing the awkward silence that had fallen over Professor Vector’s office. “Yeah, I, uh, did lots of proofs. Sooooo many proofs.”

She smiled. “To what end? What are you hoping to do with this? A new spell, or something... else?”

“Spell, spell for  _ sure _ ,” said Barry, shaking his head a little. “I, uh, you know I’ve never been one for potions.”

Vector laughed a little. “I’ve heard Severus’s stories about your, ah,  _ escapades  _ in potion making during your earlier Hogwarts years.”

“So, uh, a spell. I’m thinking something, uh, like... like a connection spell? And a placement thing? Like, if I cast the spell on you and me, it activates the bond between us, and depending on how strong that bond is, we’re connected.”

“Connected in what way?” Vector leaned forward on her elbows, tea forgotten. “Physically? Emotionally, like an empath?”

“I was thinking, like... you can speak to each other? Mentally?”

“Telepathy?”

“Uh, yeah, that. But more like, you can sense where they are and like, what’s happening to them, if that makes sense? Send them some of your magical energy?”

“Why-- why on earth would you want to send somebody your magical essence?” Vector asked.

“Uh, a temporary sending,” Barry said. “Like, if they’re getting hurt, you can give ‘em a boost of magic to help them out.”

She nodded slowly, and picked up her teacup, but didn’t take a drink. “That does sound useful, if more useful in a combat scenario. Do you think you’ll have cause to use it?”

Barry shrugged. “It, uh, it never hurt to be prepared, right?”

“You make a good point. So, for the mathematical aspect, are you thinking that a derivative of the bonds would most accurately connect them?”

“Well, I was thinking about doing, uh, an integral,” Barry said, digging a piece of scratch paper out of his book bag and spreading it out onto Vector’s desk. She passed him a pencil, and he drew a quick curve. “If you set up the spell to map the, uh, the curve of their relationship? You’d have to set up a curve that’s mostly applicable to all relationships, and then have an undefined constant to account for that--”

“Back to the integral?” suggested Vector, finally taking a sip of her tea, and setting it back in it’s saucer with a quiet clink.

“Oh, yeah! Sorry, uh, got off topic.”

She smiled. “No worries.”

“So you set up the graph, right--” Barry sketched a quick curve-- “And if you take it’s integral, you get this area--” he shaded in the area between the graph and the x axis-- “And I figure that  _ that  _ area is like, all the stuff that actually makes up the relationship. That’s the stuff that built the bond.”

“How do you mean?” she tilted her head to the side. “We’re working in mathematical abstractions, Barry, not...  _ emotions _ and such.”

“But they’re  _ connected _ ,” he said, gesturing a little. “I mean, like, these bonds are just maths and physics. And they’re all about relationships between people! And every experience anybody has-- like, this conversation right now, is increasing our bond in a specific way! And of course we’d have to factor in different emotions... maybe a different axis per emotion...”

“It sounds like you could be onto something,” said Vector, as he began to ramble. “Let’s write this down and see where it goes.”

\---

“Goin’ to Hogsmeade tomorrow?” Merle asked Barry that evening as they ate dinner. It was the first Hogsmeade holiday of the school year, and even with a small class load Barry had been looking forward to the break.

He nodded. “Yeah, absolutely. I’m going down with Lup.”

“Taako? ‘Cretia?”

Barry shook his head, sadly. “Nah. Luce is going down with Daphne Greengrass-- she told us-- and you know how it is with Taako.”

Merle nodded sagely. “Yup. It’s tricky enough havin’ me ‘n Dav go together and lettin’ him keep up his, uh...” he dropped his voice to a whisper, “persona thingy.”

Barry chuckled wryly. “Yeah. Yeah, that makes sense.”

“Wanna walk down to the village together?”

He shrugged. “Sure, if you want us intruding on your date.”

“I firmly believe that  _ we’ll  _ be doin’ all the intrudin’,” Merle said, with a wink.

“OLD MAN,” shouted Magnus from the next table. 

Without turning around to see him, Merle raised his hand in the air over his head and flipped him the bird.

“Mister Highchurch!” said McGonagall. 

“Sorry!” said Merle, with a shit eating grin up at the professor.

“HEY OLD MAN,” Magnus shouted again.

“WHAT?” Merle shouted back, still not turning around. 

Magnus caught Barry’s eye and mouthed, “Tell him to come over here.”

“Magnus says he wants a beer.”

“I DON’T HAVE A BEER,” Merle yelled.

“Mister  _ Highchurch _ !” said McGonagall, again. “Mister Burnsides. If you need to talk, stand up and talk to each other.”

Magnus sighed deeply, gave Ron Weasley a high five, and stuffed a forkful of chicken into his mouth before hopping up from the Gryffindor table. He hurried around the long table and over to where the Hufflepuffs were sitting, and squeezed in next to Merle.

“So, old man,” Magnus began conversationally. 

Merle turned and looked at him, at least two heads shorter. “Is that any way to treat your  _ elders _ ?”

“You’re both sixteen,” Barry pointed out.

“My birthday’s first,” said Merle.

“No it’s not!” Magnus protested.

“How would you know?”

“I’ve known your for  _ seventy _ \--”

Barry kicked Magnus under the table, eyeing the hall full of Hogwarts students all around them. And the Hufflepuffs who were looking very curiously at this conversation.

“For  _ seventy-six  _ days, at least,” said Magnus, looking proud of himself for his coverup. Barry gave him a thumbs up.

“Whadda ya want?” asked Merle, mouth full.

“Are you going to Hogsmeade?”

“What’s it to you?”

“He is,” said Barry.

Merle turned to Barry, eyes wide, comically betrayed. “How  _ dare  _ you?!” he spluttered through a mouthful of bread that sprayed crumbs as he talked.

Barry made a face at him, brushing crumbs off his robes. They were made of denim and then spelled black so from a distance they looked like they matched the rest of the Hogwarts robes. So more of  _ jobes _ , really.

And even though they  _ mostly  _ matched everybody else’s robes, the Hogwarts professors had made it explicitly clear during Barry’s first year that he could only wear them on weekends and between classes. So it was only half a ‘fuck you’ that he wore his jobes all the time.

“I just wanted to know,” Magnus said, and shrugged. “You never answer the owls I send?”

“You send  _ owls _ ?” Merle looked mystified.

“He probably left his owl on silent,” said Barry knowingly.

Magnus’s face split in a wide grin of a good good goof. “Yeah, Merle, you made sure to unsilence your owl, right?”

“You can silence an  _ owl _ ?!!”

\---

Barry met Lup in the courtyard the next morning, a little bit removed from the masses of students trying to meet in the entrance hall. She smiled like she’d just exploded a DMV when she saw him, hurrying across the courtyard and dodging a cluster of first years to take Barry’s hand.

“Hey, Bear,” she said, with a smile, kissing him quickly. “You ready for our day out on the town?”

He nodded, squeezing Lup’s hand. “Absolutely.”

“ _ Rad _ . Let’s do this!” And hand in hand with Lup-- his wife, girlfriend,  _ love _ \-- Barry ran across the courtyard, Lup a step ahead, through the crowds of Hogwarts students and out into the crisp air of the autumn morning and the well-trod path to Hogsmeade Village.

The walk went quickly with Lup’s hand tight in his and her bubbling laughter always ready to spill forth.

“So what do you want to do today?” he asked her as they entered the Village itself, the road turning to cobblestone beneath them.

“I was thinking about stopping by Zonko’s,” Lup said. “And grabbing some butterbeer on the way back?”

“Sounds perfect.”

“Aw, you’re a sap.”

Barry stuck his tongue out at her, and she laughed as they wound their way through the throngs of Hogwarts students to Zonko’s Magical Joke Shop. After about half an hour of grabbing joke supplies, dodging Hogwarts students, and trying desperately to get to the cashier to buy a nose-biting teapot and a bag of dungbombs, they escaped from the zoo that was Zonko’s.

“Success!” Lup said, punching the air with her shopping bag. 

“A resounding victory,” Barry laughed, pulling Lup out of the way of a rampaging horde of third years hyped up on chocolate and butterbeer and the excitement of their first visit to Hogsmeade. 

“Three Broomsticks?” she asked him, eyeing the crowd around the shop.

“Yeah, let’s do it.”

“You sure, Bear? That’s a big crowd.”

He shook his head a little. “I’m good, babe. I got this.”

Lup squeezed his hand. “I know you do. C’mon, let’s go see if we can get Rosmerta to sell us Firewhisky!”

He laughed as she pulled him along and into the Three Broomsticks, managing to find two seats at the bar, although when Lup asked for Firewhisky Rosmerta just shook her head and turned away, sliding them butterbeers.

“Well, it was worth a shot,” she shrugged, taking a drink from her butterbeer and then setting it down with a grin. “Geddit? A  _ shot _ ?”

Barry snickered into his own mug. “Hilarious.”

Lup grinned. “I know, right?!”

They bantered as they finished their butterbeer, pushed the empty mugs back across the counter, and pulled back on coats and jackets and mittens and scarves. It was a chilly day.

“You ready to head back to Hogwarts?”

Lup nodded. “Oh yeah. Koko stayed there, and now I gotta mail him the teapot.”

“What’s he planning to do with a nose-biting teacup?” Barry asked, amused, as they wound their way out of the Three Broomsticks, narrowly avoiding tripping over a young Ravenclaw.

Lup shrugged. “I’m sure he’s got  _ some  _ great plan. Honestly, it’s more fun if I don’t know when it’s coming. Unless it bites my nose. In which case,  _ dick move _ , Taako.”

Barry laughed as they rounded the curve of the road away from Hogsmeade. A storm had begun, sending a light drifting of snow over them. Lup shivered, and huddled closer to him. He wrapped an arm around him.

“Let’s hurry back,” he suggested. She just nodded, and they picked up the pace, eyes on a large group of Gryffindors walking back to the castle ahead of them.

They fell into step with Harry Potter and Hermione Granger and Ron Weasley, who Barry vaguely knew through Lup and Dumbledore’s army. Walking in companionable silence and cold as they listened to the heated bickering of the two seventh years just in front of them. One, Barry thought, was a Gryffindor chaser. Katherine? Clara?

But then the other one tried to grab a package she held, and the Gryffindor chaser-- Crystal? Caroline? What  _ was  _ it?-- grabbed it back. And then she shot up into the air, screaming as though burning burning burning, head flung back.

“ _ Katie _ !” her friend screamed-- oh yeah, that was it, Katie-- grabbing desperately at her feet.

“Go get somebody!” Lup shouted to Harry and Hermione and Ron, struggling to grab her wand out from her multiple layers of winter clothing.

The three of them took off running towards the school. Barry rushed up to Katie, grabbing her other foot, pulling. Together he and her friend managed to tug her out of the air, Lup getting her wand out just in time to levitate Katie’s head before she hit the ground.

“We gotta get her back to Hogwarts,” Barry said. “C’mon.”

They hadn’t gotten more than a couple feet when out of the snowstorm emerged Hagrid, keeper of the keys, flanked by Harry and Hermione and Ron. He scooped Katie out of the air, her package falling to the ground. Harry took off his Gryffindor scarf and scooped it up, careful not to touch it.

Katie’s friend was crying. Lup wrapped an arm around her. And their motley crew hurried back to Hogwarts. Through sniffles and sobs, Katie’s friend-- Leanne, Hermione calls her-- explains what happened. 

Katie had come back from the bathroom of the Three Broomsticks with a suspicious package. Didn’t seem like herself. They’d argued, Leanne had grabbed for the package, it tore, and Katie grabbed it back.

“Did you see what was inside of it?” Lup asked.

Leanne wiped her nose on her mitten. “I... something shiny? Like, I dunno... a gem? Jewelry? Sorry.”

“No worries,” said Lup. “You didn’t... touch it, did you?”

She shook her head. “No, I mean-- oh shit, did Katie touch it?! But she was wearing gloves?!”

“I’m sure Katie’s just fine,” Lup said reassuringly, but turned her head to Barry. He’d been travelling with Lup for seventy-six years, so it was easy to read her lips as she mouthed, “It must have been cursed. Maybe an artifact.”

“Why would somebody want that in Hogwarts?” he mouthed back.

Lup glanced behind them, then back to Barry. “Seems like there’s more shit going on this year than we thought.”

\---

**Notes for the Chapter:**

> Thank you all so much for reading!!! if you enjoyed this chapter, please leave a comment and kudos! they really do make my day :)


	4. Hilbert Problems: a list of 23 unsolved mathematical problems

**Summary for the Chapter:**

> A letter arrives. Also, bird puns, a gryffin dabbing, what happened to Katie Bell, and a big ask.

That evening, an unexpected owl hit Barry in the head during dinner. To be fair, it wasn’t really the owl’s fault, because Merle had said “Duck!” and Barry had said “No, that’s an owl!” and gotten a faceful of feathers for it. The owl, somewhat disgruntled, dropped a letter into Barry’s soup and flew off.

“Who’s writin’ to you?” asked Merle, curious, leaning forwards to try and get a better look at the letter.

Barry fished it out of his soup and cast a quick drying spell on it, turned it over in his hands. “No clue. It’s just got my name on it.” 

“Well, open it up, then!”

Barry slid his butter knife under the flap of the envelope, pulling it open. Thankfully, no spell burst out of it, and it wasn’t a hidden Howler. It was just a thin sheet of parchment paper, which Barry pulled out of the envelope. Merle leaned against his side to see the handwritten leader. It read:

_ Mr. Bluejeans, _

_ Please join myself and other students in my office (the Griffin statue on the sixth floor) tonight at 8 o’clock in the evening. I am sure you are searching for answers as to what happened to your friend Katie Bell, and I will do all that I can to answer your questions. _

_ Magically Yours, _

_ Professor A. P. W. B. Dumbledore _

_ Order of Merlin First Class _

_ Hogwarts School of Witchcraft and Wizardry Headmaster _

_ Supreme Mugwump of the International Confederation of Wizards _

_ Chief Warlock of the Wizengamont _

“That’s a  _ lot  _ of titles,” said Merle, turning back to his sandwich. “You think his hand cramps after he writes them all down?”

“Mhm, maybe,” said Barry, peering down at the letter. “I’m... gods, I wonder what happened to her.”

“Happened to who?” asked Merle through a mouthful of sandwich, spraying crumbs all across the table.

“Katie.”

“Who?”

“The Gryffindor seeker.” Barry refolded the letter and tucked it back inside the envelope. “She, like, started floating today on the way back from Hogsmeade? And screaming?”

“That doesn’t sound good.”

“...no. No, it wasn’t. They rushed her back up to the castle and I haven’t seen her since.”

“Well, hope she’s okay,” said Merle with a shrug. “Lemme know, yeah?”

“Yeah.” He tucked the envelope into his bookbag, and cast a quick  _ tempus _ \-- it was just after 7 in the evening. “I’m gonna go find out if Lup got the letter too.”

“Bye,” said Merle, with another spray of crumbs.

Barry stood up from the Hufflepuff table, shouldered his bag, and walked over to the Gryffindor table. After a minute or so of scanning for Lup’s newly-dyed bright blue pixie cut, he spotted it, down on the far end by Magnus and the Patil twins. 

“Hey, Lup,” he said when he reached her.

She turned around, a delighted grin spreading across her face. “Bear! C’mon, sit down!”

Magnus slid over, and Barry squeezed onto the bench at the Gryffindor table.

“What’s up, babe?” Lup asked.

“You, uh, meeting with Dumbledore?”

“Oh, this thing?” Lup asked, shifting her letter-- addressed to  _ Chalupa Yuno-Fromtivi _ \-- “Yeah, figured I might as well go. The whole house has been buzzing with everybody trying to figure out what happened to Katie. Haven’t seen Leanne, either.”

“Did, uh, Ron and Hermione and Harry get letters too?”

Lup nodded. “You can tell because Ron’s owl took one of his chicken legs and he had a very brief battle with a bird.”

“Did he win?”

She turned to Barry, raised an eyebrow. “Did a talented wizard, one who has faced off against Lord Moldyshorts, and who has almost graduated from  _ Hogwarts _ , lose a fight with an  _ owl _ ? Yeah, absolutely. What did you expect?”

Barry chuckled. “Yeah, that’s fair.”

The rest of dinner flew by with witty banter and good company, and all too soon Barry’s  _ tempus  _ spell read 7:45, and he figured it was probably time to go if they wanted to get any answers at all.

“You ready to go, babe?” he asked Lup, as conversation lulled.

“Yeah, let’s do this.” She stood from the table and offered him a hand up.

He took it, standing up, and looked across the Gryffindor table. “Should we find the others?”

“Nah, I think they left already. Let’s go see what Dumbledore wants to tell us.”

\---

Barry and Lup made their way out of the Great Hall and up the grand staircase, jumping over the sticking step and winding their way through Hogwarts’ ever-changing corridors and up staircases and through trick doors, taking a shortcut through a portrait and doubling back on themselves to avoid Peeves. But they’d timed it well enough that they arrived at the large stone gryffin statue at exactly 8 o’clock.

“How do we get in?” Barry asked, eyeing the gryffin. It seemed to eye him right back.

Lup shrugged and marched right over to the statue, with a nod. “‘’Sup.”

There was a pause. And then the statue nodded at her.

“Do you understand Common?” Lup asked, leaning closer to it. “Or are you just copying my actions?”

The stone griffin leaned closer to Lup. She looked away from it-- the griffin also looked away-- and grinned at Barry in evident delight.

“Look, babe!” she stage-whispered.

And dabbed.

And the gryffin dabbed back.

Lup  _ lost  _ it, cackling, burying her head in Barry’s shoulder. “Babe-- babe, look--”

He laughed softly. “I wonder why they didn’t carve it like that in the first place?”

“Yeah--” she managed, through peals of laughter, that slowly calmed down until she looked back at the still-dabbing statue, and Lup laughed harder. “Yeah, I-- it’s pretty fuckin’-- pretty fuckin’ lit!”

“I see you two have made friends with the statue,” said an amused voice behind them.

Barry and Lup turned around, Lup frantically trying to compose herself. Behind the two of them stood Professor Dumbledore, resplendent in purple robes that shimmered with stars and a tall, matching hat. Taako would approve of his fashion, Barry thought.

“Yeah,” said Lup blithely. “They’re pretty cool.”

The headmaster smiled, and stepped around them towards the statue. He held one of his arms to his chest-- blacked, slightly, as though it had been burnt. Or cursed. Barry could tell by Lup’s sharp intake of breath that she had noticed it too. But they’d been doing this thing for too long to bring it up now.

Dumbledore leaned to the griffin and murmured something to the still-dabbing statue. It nodded at him, and stopped dabbing (“Aw,” said Lup, disappointed.) and slid to the side. Behind it, the solid stone wall folded in on itself, forming a tall and arched doorway.

“Would you two like to go up?” he asked politely. “I’ll be right up once our other guests join us.”

“Yeah, for sure,” said Lup, taking Barry’s hand and pulling him into the doorway. “They’re sure slow, huh?”

Barry shrugged as they began to ascend the spiral stone staircase, one hand pressed up against the smooth wall for balance. “Maybe they stopped by their tower or somethin’.”

“Yeah, maybe,” she said, with a shrug, a couple steps ahead of him. “Gods, you’d think this plan would hurry up an invent elevators or somethin’ already. Maybe an escalator.”

“Yeah, that’d be cool,” Barry replied. He could already feel his thighs burning as they hiked up the steep stairs. “Maybe it’s, uh, Dumbledore’s exercise routine.”

Lup’s laughter echoed back down the spiraling staircase, ringing in Barry’s ears. And then before he could reply, they were there, standing on a landing in front of a large and somewhat imposing dark wooden door inlaid with gold runes.

“Fancy,” Lup said, prodding one of the runes with her finger. It shrunk away from her touch. “Magic as fuck, too.”

“Is it open?”

She tried the handle. “Nah-- oh, hey! Yeah, let’s bust this joint! Babe! Babe, let’s slice the pie!”

Barry chuckled. “The one time we don’t need to? You still trying to make up for Cycle 56?”

“Hey,” Lup defended, grinning, as they lined up next to the door, “That was a one-time thing. And the door looked totally normal!”

“You failed your perception check,” he teased.

“A one-time thing,” Lup repeated, and twisted the fancifully carved doorknob-- a lion’s head-- and pushed the door open. Lup and Barry stepped in side by side, scanning the room, each covering half of it as they looked for potential threats.

Thankfully, nothing attacked them. Instead, the circular room looked to be  _ basically  _ what a stereotypical wizard’s tower was. Cabinets of spellbooks and mysterious artifacts and vials. A desk covered with dainty, spindly golden instruments, each respectively smoking, sparking, or humming as though to remind you that they were magic as all get out. Gold-framed portraits of past headmasters and headmistresses of Hogwarts circled the empty wall space. Many of their occupants eyed Barry and Lup suspiciously. One of them sneezed.

“Bless you,” said Lup cheerfully, crossing the room and climbing a couple stairs to a sitting area. “C’mon, babe, might as well get comfy.”

“Sure,” he replied, following after her, looking up at the ceiling and the star chart that was painted there, glowing, and-- was it  _ moving _ ? He looked for a second longer, and watched a comet track it’s way across the ceiling and out of sight. Yep. Definitely moving.

He’d just settled down in a purple and cushy chair next to Lup-- who was kneeling on her chair backwards and examining one of the books on Dumbledore’s bookshelf entitled “Highley Advanced and Painfully Difficulte Magicks”-- when the door opened again. The headmaster, white-bearded, walked into his office, trailed by Hermione, Ron, and Harry, looking around in interest.

“Please, take a seat,” urged Dumbledore, gesturing to the chairs by Lup and Barry.

They did, somewhat awkwardly. Lup was still turned completely around and facing the bookshelf.

“Hey, uh, guys,” said Barry.

“Hi, Barry,” said Hermione. Harry waved. Ron nodded.

Dumbledore was the last to sit down. He nodded, steepling his fingers together, looking very Old and Wise and Magical indeed. “Thank you all for taking time out of your schedules to meet with me. Sixth year is a busy one.”

“Yeah, it really is,” said Hermione, shooting Lup-- who had moved on to perusing “Techniques in Mineral Rituals”-- a look. “Professor, if I can ask, why are we here?”

“All five of you were with Katie Bell and Leanne Macintosh yesterday as you returned from Hogsmeade Village,” twinkled Dumbledore, looking at them over his half-moon spectacles. “I know there have been many rumors around that subject.”

“Hit it on the nose, twenty points and a stuffed duck,” said Lup without turning around.

“Katie Bell is currently at St. Mungo’s Hospital, receiving the best of care. She was placed under the Imperius curse by an unknown subject, and instructed to deliver a package to Hogwarts.”

Ron shifted in his seat. “Uh, what was in the package? Looked like a necklace or something?”

Dumbledore nodded, smiling gently. “Indeed, Mr. Weasley. Inside the package was a cursed necklace, designed to kill whoever touched it.”

“So why isn’t Katie dead?” asked Hermione, blunt.

“She touched it with the least amount of skin possible, Ms. Granger. She had a tiny hole in her mitten.”

“And that’s why you mend your shit,” Lup whispered to Barry, having turned around, both books stacked on her knees.

“Is she gonna be okay?” asked Harry. “It looked bad.”

“She is still unconscious. But she should be perfectly fine,” Dumbledore said. “Do you-- any of you-- have any more questions?”

“What’s the purpose of clowns?” Lup asked.

“Any relevant questions?”

“It’s relevant,” Lup protested, but everybody else shook their heads.

“Wonderful,” said Dumbledore. “Again, thank you for meeting with me. Actually, Ms. Yuno-fromtivi, Mr. Bluejeans, would you wait a moment? There’s something else I’d like to discuss with you two.”

“Sure thing,” Lup said.

Dumbledore walked Hermione, Ron, and Harry to the door of his office, and closed it securely behind them before coming to sit back down in his chair. “So.”

“So,” Lup repeated, leaning forward and pressing her own fingertips together, mimicking his posture. “What’s up?”

“Six years ago, you arrived on this plane,” said Dumbledore, twinkling down at them. “And you two--” Barry figured that he was leaving out Taako and Davenport and Lucretia and maybe even Magnus, because none of them had fallen in as well as them and Merle to Dumbledore’s plans-- “You two have done nothing but help our school and our community. And for that we are thankful.”

Lup shrugged. “No biggie.”

Dumbledore smiled slightly. “Much appreciated. However, I am afraid that I must ask you for another favor.”

Barry looked at Lup and met her eyes, slightly nervous.

“Uh, yeah?” he asked. “What is it?”

“We aren’t gonna agree to anything we don’t know about,” Lup nodded.

“Of course. I would expect nothing less.” Dumbledore paused, and took a deep breath. “As you are both aware, Lord Voldemort has returned. The battle against him and his Death Eaters has begun to progress at an exponential rate. They have recruited the dementors and the giants to fight with them. They--”

“Now, hold up a sec,” Lup said, raising a finger in the air in a ‘pause’ motion. “ _ How  _ are you fighting back? Yeah, they’re shitty and shit, but what are  _ you  _ doing?”

“You are both in the Order of the Phoenix, Junior,” said Dumbledore wisely. “The  _ real  _ Order of the Phoenix--”

“Senior,” Lup muttered.

“-- has been doubling its efforts to secure the Ministry of Magic against infiltration by Voldemort and the Death Eaters. They provide protection to Hogwarts and Hogsmeade, as well as other predominantly wizarding settlements, such as Godric’s Hollow. However. Lord Voldemort cannot be killed.”

“Uh, what?” asked Barry, glancing at Lup. 

“He has created cursed magical artifacts known as  _ horcruxes _ . Each contains a small piece of his soul. Until all of these items are destroyed, Lord Voldemort as we know him cannot be killed. This is how he was able to return to life after trying and failing to kill Harry Potter.”

“Shit,” Lup said. “So the Order’s searching for these horcruxes?”

He nodded. “I’m sure I don’t need to tell you two that this information is highly secret. If it comes out, that would be the end of our battle against Voldemort. Our great advantage is that he does not know that we know about the horcruxes.”

“So, uh, where do we come into this?” asked Barry. “You want us to help you find them?”

Dumbledore smiled at them, and shook his head slowly. “Interplanar travellers though you may be, you are still students under my protection. You deserve the chance to attend Hogwarts in safety.”

“So what do you want?” Lup asked, eyes narrowing slightly. "This feels like it's gonna be a big ask."

“We don’t necessarily need your help to locate the horcruxes, but you do have something that could provide us with more power. It would help us locate them faster and easier. And not only that, it may aid us in their destruction.”

“What  _ is  _ it?” asked Lup, tensing. Barry put a hand on her arm, gentle. 

“I would ask you two to give the light of creation to the Order of the Phoenix.”

\---

**Notes for the Chapter:**

> Thank you so much for reading! If you enjoyed this chapter, please please please send me a comment or kudos to let me know!


	5. Axiom: a starting point for inferring truths and theorems

**Summary for the Chapter:**

> Dumbledore's request. Also, technically correct answers, alarms, and the true power of the light of creation.

Lup  _ laughed _ . “Give it to you? No. Absolutely not. I--”

“I’m afraid you do not understand, Ms. Yuno-Fromtivi,” said Dumbledore. “We would merely be borrowing this light. It would be returned to you just as soon as all of Lord Voldemort’s horcruxes are destroyed.”

“This, uh, this isn’t our decision to make,” Barry said quickly, before Lup could do something like light his beard on fire. “We’d have to talk to the rest of our crew--”

“And we for sure couldn’t  _ give  _ it to you, d’you want your plane to survive the Hunger or  _ not _ , what if it comes earlier than we’d projected--?”

Maybe we could help you out?” Barry offered. “Bring the light of creation with us and let you use it to find and destroy these horcruxes and then store it safely?”

“Discuss it with your crew,” said Dumbledore, but his eyes were hard. The absence of their usual magical twinkle was disconcerting. “Think about it, Mr. Bluejeans, Ms. Yuno-Fromtivi. If these horcruxes are not destroyed, Lord Voldemort and the Death Eaters  _ will  _ rise to power.”

“Do you have other ways to find them?” Lup challenged. “To destroy them?”

“We have potential methods--”

“Then use those.”

“Just discuss it,” said Dumbledore. Had the lights in his office gotten less bright, Barry wondered? Weird. “You could save thousands of lives.”

“Great,” said Lup, her face closed off as she stood, hoisting the books she’d slid from Dumbledore’s overstuffed bookshelves under her arm. “We’ll get back to you.”

Barry followed Lup as she marched to the door. When he turned around to close it behind them, he saw Dumbledore standing in the middle of his office, watching them leave, his face closed off, hard.

They didn’t dare speak about what had just happened until they were well away from Dumbledore’s office, in the maze of corridors at Hogwarts.

“Are we actually even thinking about this?” asked Lup.

Barry paused, and then shook his head slowly. “I, uh, I don’t think so. I mean, maybe helping him and the Order use it? But I don’t think it’s safe to just... give to them.”

“Exactly! Plus, our calculations about how long we’ll be on this plane have the possibility of a margin of error,” said Lup. “If they don’t get it back to us, and the Hunger is early-- if we get surprised without the light of creation-- that’d be  _ it  _ for this plane. After everything we did to get it!”

“Yeah, yeah, I’m with you,” said Barry. “I think we should tell everybody else about it, though.”

“This can’t wait for the Thursday meeting,” Lup said, and a smile flickered across her face like a flame. “Wanna go break into the Ravenclaw tower and find Dav?”

“I could just send Jorts to him with a letter,” Barry pointed out.

Lup smiled a little wider. “Yeah, babe, but where’s the  _ fun  _ in that?”

He smiled. “You’ve got a point.”

Hand in hand, Barry and Lup climbed another couple staircases to reach the Ravenclaw tower. By the time they arrived at the large wooden door with it’s eagle-headed knocker, Barry was out of breath, panting, and even Lup looked a little winded. Still, after only a moment to catch her breath, she straightened up, and banged the knocker against the door.

“What is the difference between love and trust?” asked the eagle, serene.

“They’re spelled differently,” said Lup blithely.

“That... is technically correct,” the knocker said, sounding like it had a grudge. Barry chuckled slightly as the door swung open.

Lup marched right into the Ravenclaw common room without bothering to look around or greet any of the Ravenclaws-- maybe two dozen of them-- who were in the common room, reading and painting and sewing, casting charms and curses and anything else they could figure out how to do. To their credit, none of the Ravenclaws gave Lup and Barry a second glance as the door closed behind them.

Lup led Barry through the comfortable-looking couches and cushions, to the back of the room, and ducked under a curtain he hadn’t noticed before.

Suddenly they were in a small window nook, no bigger than a closet, but with a tall window and a great view of the Black Lake, candles floating in the air and books in shelves and a cushioned window bench upon which Davenport stood, his wand out and pointed at them. As they made eye contact, Davenport somewhat sheepishly lowered his wand.

“Hello, Lup, Barry,” he said. “What’s wrong?”

“Dumbledore wants us to give him the light of creation.”

“He wants  _ what _ ?!”

“Yeah,” said Lup, and now she looked worried. “So-- ugh. Moldyshorts has these things called horcruxes, and there’s a piece of his soul in each of them, and basically he can’t be killed until the horcruxes are all destroyed. Oh, this is all secret, by the way.”

Davenport nodded. “Of course it is.”

“So he wants to borrow the light of creation to help the Order of the Phoenix find these horcruxes and destroy them,” Lup finished. “We told him we’d need to talk to everybody else before we came up with a decision.”

“Well...” Davenport sighed. “Maybe there’s a middle ground. We can’t just give it to him; we can’t doom this plane.”

“Exactly!” said Lup, throwing her hands in the air. “ _ Exactly _ ! Like, Bear and I  _ tried  _ to give him suggestions for a middle ground but he was all avoid-y about the whole thing.”

“Barry?”

Barry sighed. “I, yeah. I’m with Lup. Of course we should help, if they’ll let us, but... we gotta help everybody, y’know? And I don’t trust Dumbledore to keep track of the light. It has a tendency to wander off.”

“Speaking of, where  _ is  _ the light?” asked Lup.

“It’s on the Starblaster,” Davenport replied. “But it’s perfectly safe: I’ve got it protected. The whole ship and clearing are warded to the Astral Plane and back. Plus I have a Glyph of Warding set on the ship-- if anybody who’s not one of us or Fisher tries to board the ship, my wand will start to beep and blink.”

“Oh, like an alarm,” Lup said.

“Yeah. Just like--”

_ Beep! Beep! Beep! Beep! _

All three of them in the window seat looked at Davenport’s wand as he held it aloft. It beeped, loudly. And it was blinking bright red.

“...just like that,” Davenport finished, with a sigh.

“Somebody’s trying to get on the ship,” Lup concluded.

He nodded, tearing aside the curtain and rushing out, back into the Ravenclaw common room, Lup and Barry right behind their captain. They ran to the window-- Lup pulling a shrunk broom from her book bag and Davenport summoning a pair of brooms for himself and Barry-- Lup shattered the window with a quick spell-- and the three of them dove out, to the scattered cheering of the confused Ravenclaws behind them.

\---

Barry, Lup, and Davenport soared around Hogwarts and above the gnarled, snow-dusted trees of the Forbidden Forest. The icy cold air of the evening stung Barry’s face, and he could feel the chill even through his denim robes (jobes). He squinted into the wind, flying behind his captain as Davenport led the way through the winter night.

They reached the clearing where the Starblaster was parked quickly, descending through the spindly leafless branches like claws and down to the snowy ground.

The Starblaster, silver and beautiful and shining under the light of the moon, stood before them. 

“I don’t see anybody on it,” Lup whispered, already running for the ship. “We gotta do a sweep of it.”

Davenport nodded sharply, climbing back on his broom and rising into the air, like this was just another game of Quidditch for him. “I’ll look from above, test the wards. The light of creation is in there-- be ready for anything.”

Barry ran after Lup, a couple of steps behind, and up the gangplank that unfolded itself from the Starblaster the second they got close to it. His wand was steady in his hand.

But Barry and Lup didn’t have far at all to go: immediately in front of them, in the main hallway of the Starblaster, stood a far too familiar figure.  _ Dumbledore _ .

“Hello, Professor,” said Lup casually, spinning her wand between her fingers. “Fancy finding you here, isn’t it?”

“Indeed, Ms. Yuno-Fromtivi,” twinkled Dumbledore, as though he wasn’t pointing his wand directly at them. “Now, would you please direct me to the light of creation?”

“Fuck no,” Lup spat, pressing closer to him. “We would’ve  _ shared  _ it with you, you know.”

“We didn’t have time for that.”

“And you have time for a  _ duel _ ?” 

“Preferably, no,” he said, perfectly mild. “If you would just direct me to the light, we can avoid all this unpleasantness.”

A sneer carved it’s way across Lup’s face, and a burst of fire bloomed from the end of her wand, billowing like waves towards Dumbledore--

It turned into a gust of air with a wave of his wand, and a lion formed from nothing, rushing at Lup--

Which transformed into a mouse, scurrying between her legs, and then an acid splash flew towards Dumbledore--

Lup had it under control. Wand in hand, Barry vanished from view, running through the Ethereal Plane to the end of the hallway and into Davenport’s room. Wand raised, he cast True Sight-- gods, it was a good thing that this plane didn’t know the spells he and the rest of the crew did, or Dumbledore would’ve had the light in minutes-- and grabbed the light from it’s hidden location, after hacking through a couple more arcane locks.

A cloud of smoke blew under the door to Davenport’s room. That... probably wasn’t good. But Barry was holding the light of creation, and with it, everything seemed so  _ simple _ .

A quick and silent  _ Alohamora  _ opened the door and Barry stepped into the smoky corridor, with his wand in one hand and the light of creation in the other. It was easy, to cast a shield spell so thick he could barely see through it. And it was easy, to walk forward, pushing back Dumbledore despite the man’s assaults on Barry’s shield. Bursts of fire and lightning erupted from Dumbledore’s wand, but Barry couldn’t even feel the heat.

Lup blinked out of existence as Barry forced Dumbledore to the end of the hallway. The man was shouting, yelling, casting spells that scorched the walls and made the light fixtures spark.

\---

See, the light of creation was all about bonds. It allowed the wielder to use the strength of their bonds to impact the world all around them. 

And Barry was, as prophesied, a lover.  _ The  _ lover. He loved and cared so deeply and fiercely: about his family, about his wife, about each and every plane the Starblaster touched down upon. 

And when Barry wielded the light of creation in protection, in love-- to save Lup, to save the Starblaster, to save that mostly wonderful and innocent plane from certain destruction-- the light of creation amplified Barry’s bonds ten times, a hundred times, a thousand.

And no wizard, no matter how brilliant or wise, could possibly compete with that much love.

\---

Barry blasted Dumbledore out of the Starblaster and into the snow.

“Fuck off!” shouted Lup, triumphant, her voice distant and distorted by the shield spell that Barry still held up. 

He dropped the shield, light of creation tight in one hand and wand in the other, and ran to the edge of the ship as it began to purr slightly beneath his feet.

“Liftoff!” shouted Davenport from his place at the wheel.

Barry watched over the edge of the Starblaster as their ship lifted into the air, the small figure of Dumbledore getting smaller and smaller beneath them as he slowly climbed back to his feet.

“We can’t go back to Hogwarts,” Barry said, with perfect certainty. They had just attacked-- and defeated-- the Headmaster himself. No matter how good their excuses were, there was no way that he, Lup, and Davenport would ever be safe at Hogwarts again.

“We have to get out of here!” Lup said, leaning over the side rail, as the small figure of Dumbledore in the Forbidden Forest brandished his wand at the ship.

“Hold on!” Davenport yelled. Barry tucked his wand into the pocket of his robes and grabbed the handrail. Next to him, Lup did the same.

And, with a rush of air and punch of sound, the Starblaster  _ soared _ . Over the Forbidden Forest and the candle-lit Hogwarts, over the snow-dusted village of Hogsmeade and the Scottish highlands. Away, away, away.

\---

**Notes for the Chapter:**

> whoo boy that chapter was a doozy! if you haven't noticed, we are definitely moving away from following the plot of the Harry Potter books. I hope you're all enjoying this!!
> 
> if you liked this chapter, i would love to hear what you think! kudos and comments make my life 420% better


	6. Fourier Series: complex periodic functions made of simpler functions

**Summary for the Chapter:**

> Barry, Lup, and Davenport on the Starblaster. Also, giving the light of creation a bath, the sacred tradition of nose goes, everybody's favorite owl, and a big old planning session.

“So what are we gonna do now?” Lup asked conversationally, when Davenport finally slowed the Starblaster to hover over the middle of some ocean whose name Barry didn’t know. There was nothing but water to be seen in any direction that he looked, and the air tasted like salt.

Davenport sighed, running his hand along the steering wheel before walking away to join Lup and Barry at the railing. “I think first we need to figure out what just happened, Lup.”

Lup shrugged. “Dumbledore went batshit crazy. Easy.”

“Or,” said Barry, pushing his glasses up his nose. “Or it was the thrall.”

“What do you mean, Barry?” asked Davenport.

“Well, I mean-- it’s the thrall of the light, right? Uh, remember all those mushroom people, on Fungsten? How they all, like, worshipped the light? And remember on the jello world, uh, remember how whoever had the light would do anything to protect it?”

Lup nodded slowly. “Dumbledore was too close to the light for too long, maybe. And that made him be willing to steal it from us. Why didn’t he do that, uh, any fuckin’  _ sooner _ ?”

“Desperation?” Davenport suggested, hands on the railing tightening for a split second. They’re at war, or, they almost are.”

“Still doesn’t excuse that shitbag,” said Lup.

Davenport shook his head. “Of course it doesn’t.”

“So, Dumbles got himself thralled, thought the best solution was to steal the light from us. Cool, cool, super cool,” said Lup. “And now we’ve got the light-- we do got it, right?”

“Uh, yeah,” said Barry, fishing through the pockets of his denim-jean robes. (Jobes.) After a couple moments of leafing through spare quills, chocolate frog cards, scraps of parchment, and the old golden galleon from Dumbledore’s Army, he pulled out the light of creation.

“Babe,” said Lup, leaning closer to it, wrinkling her nose. “There’s a stick of gum stuck to it.”

He looked down at it. A stick of partially-unwrapped, slightly-melty pink gum had adhered itself to the light of creation. “Uh.”

“Nose goes,” said Davenport, his own hand already on his nose.

Barry got to his own nose just a split second before Lup did, smacking himself in the face. But it was entirely worth it.

“Gods  _ dammit _ ,” Lup moaned, taking the light of creation from Barry and walking across the deck. “I had to give the damned thing a bath  _ last  _ cycle!”

“You lose nose goes,” said Davenport, hiding a smile. 

“It’s a, uh, sacred tradition,” Barry added.

“ _ Ugh _ ,” said Lup, disappearing belowdecks to try and wash off the light of creation, which really didn’t like being washed.

“So,” said Barry, turning back to Davenport. “Any ideas on what we’re gonna do now?”

Davenport sighed, staring over the railing of the Starblaster and down into the ocean far below them. “Well, we can’t go back to Hogwarts. Hopefully the thrall will have worn off of Dumbledore by now, and he can be sensible about this, but... we did attack the Headmaster.”

“And win,” Barry added. “We, uh, we did win.”

The captain smiled. “Yes, we did. But... barely. It was lucky that we made it back to the Starblaster before Dumbledore could break my arcane locks. Besides,” he sighed again. “If he doesn’t try to steal the light again, odds are that somebody else will. We made it for six years with the light of creation safe in the ship-- after we stole it from Lockhart-- and at that point we were pushing our luck.”

Barry nodded. “We’ve never had to hide it for more than a year before. And it’s got, uh, that good good craveability.”

He shook his head, smiling slightly. “It’s like Magnus is standing next to me. So... well, let’s wait for Lup before we plan any further.”

\---

They didn’t actually end up planning any further until they were all in the kitchen after dinner, doing the dishes. Well, Barry and Davenport were doing the dishes. Lup was sitting on the countertop, trying to see how many spoons she could stick to her face.

“So, gang,” said Davenport, handing Barry a spoon to dry. “I’ve been thinking about what we’re going to do now.”

“Radical,” said Lup, taking the spoon from Barry. 

“We can’t go back to Hogwarts. We can’t count on Dumbledore not getting thralled again, and gods  _ know  _ what he’s told the rest of the school about us. So we’re going to let the rest of the crew know what happened, and get them to find out what’s going on at Hogwarts.”

“Maybe get them to send us our stuff,” Lup suggested, scrunching up her face, trying to get a spoon to stay on her cheek. “I  _ just  _ got some of that good good Zonko’s stuff.”

Davenport nodded, and passed Barry a just-washed and dripping wet pot for him to dry. “We’ll see what we can do. But once we do that, I think we stay in the Starblaster, and keep it moving. Dumbledore and his adherents are incredibly competent wizards--”

“Psaw,” Lup scoffed, sending all the spoons on her face clattering down to the floor. “Damn it. He’s not as good as he thinks he is.”

“But there are spells on this plane that we don’t even know about,” Davenport reminded her. “And I’m not washing those spoons again.”

“Dadn’port, c’mon--”

“So we’re going to stay with the Starblaster,” he continued, speaking over Lup’s muttered complaints about the spoons. “And we’re going to stay out of the way of everything that’s going on in Europe with the wizarding war.”

“Aw,” Lup complained, hopping off the counter to pick up the spoons. “That’s no fun.”

“We could go, uh, help?” Barry suggested, setting the now-dried pot aside for Lup to put away. Or try to stick to her face. “The others could let us know if, uh, if shit’s poppin’ off?”

Davenport turned away from the sink, hands soapy, and looked between Lup and Barry. Lup did her best puppy dog eyes. Barry shrugged. Davenport sighed. “I’ll think about it.”

“ _ Yes _ !” Lup said, with a fist pump. 

“We’ll call the others tonight,” said Davenport. “Who do you think--”

“Uh, Lucretia,” Barry said. “I mean, uh, Taako can’t ‘cause he’s playing bad cop, Magnus’ll get all teary about everything, and I bet Merle hasn’t even noticed we’re gone yet.”

“It’s date night,” said Davenport, turning back to the last of the dinner dishes. “I certainly  _ hope  _ he’s noticed we’re gone.”

“We’re just teasin’, Dadn’port,” said Lup. “Bear’n’ I’ll go Floo Creesh. We’ll ask her about Merle, and try and get him to Floo us.”

“Thank you, Lup,” he replied.

“No problemo,” she said, shooting him finger guns with one hand and grabbing Barry’s hand with the other. “C’mon, babe. We gotta call our girl.”

\---

They briefly considered waiting until late that night to call Lucretia, in the hopes that the Ravenclaw Common Room would have emptied out by then. But-- after remembering just how late the Ravenclaws tended to stay up-- Barry and Lup decided that the better course of action would be to call her immediately and hope some first year had gone straight up to the Common Room after dinner.

“Got the Floo powder, babe?” asked Lup, stepping away from the magical bonfire she had just lit on the deck of the Starblaster, for want of a fireplace.

“Right here,” said Barry, lifting the jar of green powder he held in his hand. “Ready?”

“Take it away.”

He carefully unscrewed the lid of the jar and pulled out a pinch of the powder, flinging it into the bonfire Lup had made. “Ravenclaw Common Room!”

The fire flashed green, and Lup dropped to her knees and stuck her head in. Barry put the lid back on the jar, tucked it into the pocket of his jobes, and knelt down next to her, sticking his head into the fire. It tickled, slightly, and for a second there was nothing but green flames. But then before their two heads rose the Ravenclaw Common room, with looming couches and sculptures and stars on the ceiling. The fireplace was a really great angle to appreciate the chandelier, too.

But the room appeared to be empty.

“Fuck,” Lup hissed, then shouted, “Hello?! Anybody there?”

Across the room, from somewhere out of their sight, somebody said, “Yes.”

“Hey, hey hey hey,” said Lup, exhaling a relieved laugh. “Can you come over to the fireplace, babe? I need to ask for a  _ hell  _ of a favor.”

Winding around the furniture came-- not a first year, as they had hoped for-- but a fifth year. Luna Lovegood.

“Luna!” said Lup, delighted, grinning up at her. The two had met in Dumbledore’s Army and hit it off pretty well. Barry was  _ very  _ glad he had Lup with him right then, because he’d never been great at talking to others, even in the D.A.

“Hello, Lup and Barry,” she said, looking faintly puzzled, and wearing a large pair of colored spectacles that made her eyes seem larger than life. “Why are you flooing the tower?”

“We were trying to talk to Creesh,” said Lup. “Do you know where she is?”

Luna closed her eyes, and then nodded. “She was called in to meet with Professor Dumbledore. She got a letter when we were eating dinner together.”

“That can’t be good,” Barry muttered, and Lup nodded slightly.

“Luna, babe,” she said. “Can you tell Creesh we called? And as her to floo us back when she gets back?”

“Of course I can,” said Luna. “But wouldn’t it be easier to send an owl?”

“Uh...” said Barry. “Actually, yeah, probably. Uh, tell her to send Jorts to let us know when she can talk?”

“Jorts is a funny name for an owl,” Luna noted.

“It’s a nickname. His full name is, uh, Hoots McBluejorts.”

Luna’s brow furrowed, and then she laughed like a bell. “I’ll tell Lucretia.”

“Thanks, Luna,” said Lup. “Catch ya around!”

And Lup pulled her head out of the bonfire. 

“Um, bye,” said Barry, very quickly retreating to follow Lup.

They knelt side by side on the deck of the Starblaster. Lup pulled her wand out of her robes and casually doused the fire.

“So,” said Barry. “Talking to Dumbledore?”

“Can’t be good,” Lup said, shaking her head. “But Creesh’s pretty badass. She’ll be fine. And she’ll send us an owl soon as she can.”

“Yeah,” said Barry, with a sigh. “Yeah. It’s all gonna be okay.”

“Fuck yes it is,” Lup said, pushing herself to her feet, and then offering Barry a hand. He took it, and she pulled him to his feet. “Let’s go tell Dadn’port what’s goin’ on.”

\---

Jorts the owl arrived at the Starblaster just before midnight, with a small scroll tied to his leg. Lup quickly untied it, while Jorts hooted at her, before fluttering over to perch on Barry’s shoulder.

“What’s Creesh got to say?” Barry asked, feeding Jorts an owl treat that he’d been glad to find in the back of one of the kitchen cabinets.

“She got questioned by Dumbledore about where the rest of us went... So did Merle ‘n Koko ‘n Maggie, but they’re all fine... The official story Dumbledore told the rest of the school is that we’d been pulled out of Hogwarts by our families and sent to Ilvermorny...” Lup looked up from skimming Lucretia’s letter. “That makes no fuckin’ sense. Why would they send me but not Taako?”

Barry shrugged. “She say, uh, anything else?”

“Let’s see...” Lup shook the parchment slightly, flattening it out, and kept skimming. “Okay. We shouldn’t floo again, ‘cause there’s a tracking system on it. Student safety or some shit. Uh... oh, cool. Bear, look at this!”

Lup tapped the parchment with her wand, and suddenly it elongated-- and then another piece of parchment, slightly thicker, split apart from it, Davenport catching it just before it could fall to the floor, and turned it over in his hands. “What’s this?”

“It’s one of those communication parchment thingys,” said Lup, delighted, looking back at Lucretia’s letter. “She and Daphne Greengrass’d had a set but she borrowed Daphne’s to send it to us. All we gotta do is write on this and say the password and it’ll show up on Creesh’s parchment.”

“That’s great,” said Davenport, nodding as though to punctuate his point. “So, what are we waiting for?”

“Anybody got a pen?” asked Lup. Barry dug one out of the pocket of his jobes and handed it to her. She pulled off the cap, took the paper from Davenport, and flattened it out on the kitchen table where they sat. “Rad.”

Barry leaned over to see Lup write:

“ _ Sup Creesh _ .”

Seconds later, Lucretia’s reply appeared. “ _ Lup!” _

He watched as the two talked as quickly as they could over the parchment, handwriting scribbly. Lucretia confirmed that she was fine, and that the others were fine too. Dumbledore had told the professors that Davenport, Lup, and Barry had transferred to Ilvermorny, although Taako was spreading the story that Lup had gotten a little too rebellious for their parents, thus helping cement Lup and Taako’s fake parents as aligned with the dark side.

Through a team effort, Magnus, Lucretia, and Merle had gathered their trunks and other personal belongings, although they didn’t have a way to send them to the Starblaster with the Floo Network being tracked.

Merle had indeed noticed that they were missing when Davenport was late for date night.

And, perhaps most importantly of all--

“ _ McGonagall says she still expects you three to turn in your essays on Monday _ .”

They’d needed something to break the heavy tension And there, late at night crowded around the kitchen table on the Starblaster, flying over some unfamiliar sea, Lup and Davenport and Barry  _ laughed _ . Everything was messy, but it would be alright. They would be alright.

\---

**Notes for the Chapter:**

> thank you so much for reading!! if you liked this chapter, please leave a comment and kudos!!


	7. Greater Than: an inequality between two numbers or groups

**Summary for the Chapter:**

> Barry, Lup, and Davenport, and what they've been up to on the Starblaster. Also, Fantasy Dancing Queen, uptown elf, and something surprising.

“ _ Please  _ tell me we’re not gonna just fly around for the rest of the year,” Lup moaned, after a month onboard the Starblaster. They’d crisscrossed the ocean a couple of times and circumnavigated the plane, eaten some very good and some very bad fast food, and narrowly avoided a hurricane. She was sitting perched on the back of the couch, kicking her heels against the back of it. “I’ll  _ die  _ of boredom.”

“I’m sure Fantasy Dancing Queen is in here,” Barry said, comforting, from across the room where he stood flipping through their collection of music from seventy-odd different planes. “You’re not gonna die.”

“At least when I die I won’t have to live in a plane where  _ somebody _ \--” Lup very dramatically flopped backwards onto the couch, glaring at Davenport, who sat curled up in an overstuffed armchair, a thick book open on his lap, “--didn’t misplace the Fantasy ABBA!”

“It wasn’t me,” said Davenport, turning the page.

“Who was it, then?”

“Taako, probably.”

“I-- okay. That’s fair. But  _ still _ . Capn’port, there’s  _ nothing  _ to do.”

“We need to do some repairs in engineering,” he suggested without looking up. “You can--”

“Fuck no, I didn’t mean I wanted to do  _ work _ . Babe? Any suggestions?”

“I found Fantasy Uptown Girl.”

“Yeah, okay,” Lup said, sighing dramatically.

Barry set the record onto the player, and it started to play.

Lup sang along, fucking with the lyrics the whole way.

“Uptown elf... she’s been sitting there up on that shelf... I bet she’s never flown to outer space... I bet she never saw a prettier face...” she pointed at Barry as she sang the last line, and winked.

“If you start kissing I’m going to leave,” said Davenport mildly.

“I’ll keep that in mind,” Barry replied, turning back to their collection of records and leafing through them. Where  _ was  _ the Fantasy Dancing Queen?

“I’M GONNA TRY FOR AN UPTOWN ELF,” Lup sing-screamed. “I BET SHE REALLY LIKES TO KISS A... HELF.”

Fantasy Hotel California, Fantasy Jolene...

“AND NOW SHE’S LOOKING FOR A DOWNTOWN MELF.”

“The creator of Melf’s Acid Arrow?” asked Davenport.

Fantasy Mr. Blue Sky, Fantasy Shut Up and Dance...

_ Thump _ .

Barry looked up. “Did you hear that?”

“SHE’LL SEE I’M NOT SO TOUGH JUST BECAUSE I’M IN LOVE WITH AN UPTOWN ELF--”

“Lup, stop,” said Davenport. “Barry, what?”

“You know I’ve seen her in her uptown world,” Lup said, very quietly, as the music blared.

“I thought I heard something.”

“Besides the music, and what Lup thinks is music?”

“I’m a great singer, fuck off,” she said, flipping off Davenport.

“No, I thought I heard something different.”

Davenport sighed quietly, slid a bookmark into his book, and closed it, setting it aside. “C’mon, crew. Border check.”

“Aw, that’s Maggie’s job,” Lup complained, even as she stood up and followed Davenport to the door.

“And Magnus isn’t here,” he replied. Barry set Fantasy Livin’ on a Prayer back into it’s box, and followed them out of the room. “Follow protocol. We don’t have enough people to do the buddy system, so stones of farspeech  _ on _ .”

“Got it,” said Lup. Barry reached into his pocket and flicked his stone of farspeech on, pulled out his wand, and gripped it tightly.

He followed Lup and Davenport out onto the main deck of the Starblaster, which was a clear and empty as they had left it earlier that day.

“Barry, port. Lup, starboard,” Davenport directed, wand in hand, as he turned to walk to the front of the ship.

Barry turned left, and Lup turned right. They stayed quiet, because this was protocol, and they were the only three to defend the ship, and they had the light of creation. Normally, life onboard the Starblaster wasn’t so tense, so terrifying. But sometimes it was, because the lives of millions of mostly innocent souls depended on them. And this was one of those times. And with the weight of this world and a million others on his shoulders-- and with Fantasy Uptown Girl playing very quietly in the distance-- Barry started to walk.

\---

The walkway was clear, suspiciosly so. And so Barry kept a careful eye over the railing, wand outstretched, just in case somebody or something was attacking from the side or bottom.

Of course, there was a chance that the  _ thump  _ he’d heard earlier was simply a very stupid bird or high-jumping ocean creature that decided to run directly into the only obstacle anywhere in sight that hovered a couple of feet over the crashing ocean waves. But there was also a chance that it was an actual threat.

So when Barry saw the dark-robed figures on broomsticks, zooming towards the Starblaster, wands extended and firing spells at the hull, he really wasn’t that surprised.

“Lup! Dav!” he shouted, the stone of farspeech in his pocket picking up his words as Barry ran along the walkway, closer to where they were attacking. “I’ve got, uh, three! Death Eaters, I think! On brooms!”

There was a sudden  _ pop  _ and rush of air from behind him, and Barry felt the sharp tip of a wand be pressed to his throat. “Oh, very good,” said a low and raspy voice. “The boy’s smart. But not smart enough to think of an anti-apparation shield, huh?”

Two more pops, and the other two black-robed Death Eaters appeared on the Starblaster in front of Barry.

“Uh, hi,” he said.

The Death Eaters were wearing masks, but he could still tell that the one in front, the slightly shorter one, was arching an eyebrow in his direction. “The Bluejeans kid.”

“Yep,” said Barry.

“He’s one of Dumbledore’s cronies.”

“Now, hey,” said Barry. “I wouldn’t--”

The wand pressed further into his throat, and he gagged, immediately stopping talking.

“We’re looking for the powerful artifact you’ve got on your fancy little ship here,” said the one behind him, a low and rumbling growl. “Now, be a good little boy and show us where it is, yeah?”

Barry coughed, to remind them that he couldn’t speak with the wand shoved into his throat. The Death Eater pulled it back slightly.

His mistake.

Barry wouldn’t call himself a fighter, but it was impossible to live around his crazy family for decades and  _ not  _ pick up a level or two. And he’d been in enough bar fights to know how to handle himself.

He  _ slammed  _ his head backwards, with a satisfying crunch as he connected with the Death Eater’s face. The shorter one in front shot a jet of crackling red light flying at him, but he blasted a shield spell towards them, sending the spell scattering off of it’s surface.

There wasn’t time to think while fighting.

Spell, shield, dodge.  _ Expelliarmus  _ and snap the wand, a spell to the gut and doubled over screaming with racking pain. Gritting his teeth and casting through it, sending one of the Death Eaters flailing over the rail of the Starblaster and down down down into the ocean below. 

Spell. Shield. Grabbing the rail and struggling to stand, limbs twitching with spell aftershocks. Spell, spell, spell-- a burst of sickly deadly green light just missing his arm-- 

“That’s  _ my  _ husband!”

Like a burst of light from the heavens, Lup appeared, red robe blazing, trailing fire from her wand. She rushed the Death Eaters-- Barry cast shield spells all around her-- and, instead, of casting a spell,  _ jumped _ , and slammed her boot into one of the two remaining Death Eaters’ chests. They went tumbling overboard in almost slow motion. Barry too rushed to the rail, casting spells down at the two Death Eaters in the water, making sure that there was no chance they’d be coming back for revenge.

The one remaining Death Eater snarled, and suddenly they weren’t playing any more,  _ Avada Kedavras  _ flung every which way. Barry and Lup were brilliantly, insanely talented arcanists, but it was difficult to show off their fancy spellwork when it was all they could do to dodge the green rays of instant death.

Just as Barry flung himself to the floor to avoid an  _ Avada Kedavra _ , the Starblaster  _ jolted _ , the bond engine rumbling faintly across the deck. And then the Starblaster  _ rolled _ .

Barry was flung downwards as the ship did a barrel roll, throwing him, Lup, and the Death Eater up and into the air-- down towards the ocean.

“Wingardium levi- _ fucking _ -osa!” shouted Lup.

And suddenly Barry was floating in midair, as Lup and the Death Eater plunged down down down--

“ _ No! _ ” Barry roared, pointing his wand. He didn’t have a spell in mind other than  _ Lup Lup Lup _ \-- and then suddenly Lup, too, was floating, upwards, back towards him. She reached out a hand, weightless, and found his.

“Do you think an upside-down kiss is too cheesy?” she asked as they floated and the Starblaster slowly righted itself under Davenport’s command.

“Absolutely not,” said Barry.

Their lips had barely met when Davenport shouted, “Can you two  _ not _ ? We have a situation?”

“Oh, goddamnit,” said Lup against Barry’s lips. “We’ll pick up on this later, yeah?”

He smiled, and they undid the levitation spells, dropping back to land on their feet on the deck of the Starblaster, close to where Davenport sat at the wheel, hands tight on it, looking out towards the horizon.

“What’s goin’ on?” asked Lup.

“ _ That _ ,” he said, pointing. Barry looked, and swallowed hard. Flying towards them on the backs of winged beasts that he couldn’t quite identify was a veritable  _ hoard  _ of Death Eaters. Faint streaks of colored light were already visible as they cast at the Starblaster.

“Those three must’ve just been a distraction,” said Lup, quietly horrified.

Davenport turned to look at both of them, face hard. “Be honest. Can we win this?”

Barry looked back at the rapidly approaching Death Eaters-- and then shook his head. “Nah. Not with just us. Not with them all using Avada Kedavra.”

Davenport nodded, once, sharply. “Both of you, hold on.”

Barry grabbed the railing, and Lup did the same, grinning. “What’s the plan, Capn’port?”

Davenport gripped the throttle, and the bond engine revved, sending a brilliant white light spiraling across the deck of the Starblaster. “Looks like Space Candlenights came early this year.”

With a punch of sound and a rush of wind, the Starblaster took flight. Barry was pushed backwards, and desperately tightened his grip on the railing. His feet flew out from under him, but he held tight as the ship turned at almost a ninety degree angle, flying straight up into the sky. The howl of air and Lup’s laughter filled Barry’s ears, and when he looked down he saw the ocean and the army of Death Eaters far below them, tiny black specks the size of ants, then small enough that he couldn’t see them at all.

There was another roar, and Davenport whooped, and the air was growing thinner and Barry felt like he was growing, being stretched and pulled in every direction--

And then they were through, out of the Plane of Magic, and into the clear black space in between planes. Barry’s legs fell back to the deck of the Starblaster. They were adults again, and Barry couldn’t begin to describe how great that was.

“Well,” said Lup, letting go of the railing. “That was one hell of a dramatic escape, Capn’port!”

“Thank you, Lup,” said Davenport, smiling slightly as he adjusted the Starblaster’s trajectory, turning the wheel. 

“Gods, imagine how  _ confused  _ they all must be,” Lup said gleefully. “One minute we’re there, the next minute-- suck it, assholes-- ‘cause we’re in motherfucking  _ space _ !”

Barry laughed. “So do we just... live in space now?”

Davenport sighed, although Barry’d known him long enough to tell that it was an amused sigh. “Looks like that.”

Lup’s eyes suddenly grew wide. “Oh, fuck. Oh, no, no,  _ no _ .”

“What?” asked Barry, rushing to her side.

She turned to him, horrified. “I know where the Fantasy Dancing Queen record is! I left it in the common room! Dadn’port, are you  _ sure  _ we can’t go back?!”

Davenport stared at Lup for a second, and then started to  _ giggle _ , a high-pitched and almost wheezy thing, hands clasped over his mouth. That was enough to make Lup start to laugh, too, one of her arms wrapping around Barry’s waist. He laughed, too, and pressed a kiss to the side of her head. In the sudden quiet, Barry could hear Fantasy Uptown Girl playing.

They might live in space now, and they might not have the Fantasy Dancing Queen record with them, but they would be okay.

\---

**Notes for the Chapter:**

> thank you for reading!! please please please drop me a comments and kudos if you enjoyed!


	8. Oscillation: movement back and forth at a regular speed

**Summary for the Chapter:**

> Good times on the Starblaster. Also, good good math, the Plane of Thought, and maybe-perfume-maybe-alcohol.

Barry was a little embarassed of how long it had taken him to do the math. In his defense, though, all of his notes on this plane’s mathematics and physics systems had been left behind at Hogwarts.  _ And  _ he’d been busy. 

There had been repairs to do to the Starblaster under Davenport’s careful supervision. There had been rooms to reorder, after everything onboard the ship got tossed topsy-turvy in their highspeed escape from the Plane of Magic. There had been food to conjure and experiments to take out of stasis and double-check and Lup. She was a distraction no matter what Barry was doing.

But even with how long his math had taken, it was done now! Barry was pretty damn sure that nobody from the Plane of Magic would be able to apparate onto the Starblaster without knowing exactly where it was (and after six years of Astronomy classes, he knew that they didn’t know about the planar system). He couldn’t be sure, though, that the Floo Network that attached the Starblaster through the chimney to the Plane of Magic had been taken offline. So really, it was safest for everybody involved to just do the math, set up some anti-apparition wards, and block the Floo Network.

In theory, it was simple.

The ward to block the Floo Network: oscillate the location of the Starblaster to zero. Make sure the frequency of the oscillation was randomized, and very fast, so it couldn’t be magically tracked down. The equation would need to change constantly, so any pursuers couldn’t track the location of their Floo by figuring out which equation Barry was using to scramble it. 

(Of course, based on the mathematic education at Hogwarts-- nothing against Professor Vector-- Barry figured that none of the Death Eaters posessed the skills or knowhow to come close to cracking his equation. But the location of the Starblaster protected the light of creation, whose presence protected this entire  _ planar system _ . So no security measure was too far-fetched.)

He’d finally come up with a suitable equation-- really, a set of equations, randomly created and then randomly selected from, to set up a bit of a double blind-- after many late nights in the laboratory. Normally Barry would bounce his ideas off of Lup, but math really wasn’t her speciality, and she got bored quickly. So he bounced his ideas off Davenport-- who got the math but not the arcana, not as much-- at dinner, and did his best to hack his way through it himself.

It did make Barry wish that he could get in touch with Taako. Taako was his best friend, sure, but he was also the only other person on the Starblaster who had the right mathematic and arcana skills. Even if Taako had sworn off of learning new math. 

(This planar system used base ten, though, so really it would’ve been  _ fine _ .)

But it was all woulda coulda shoulda at that point. Barry was on the Starblaster, Taako was making inroads with the Slytherins and Death Eaters on the Plane of Magic.

And so Barry cast the Floo Network warding spell on his own, standing outside under the infinite sparkling stars of infinite brilliant planar systems on the deck of the Starblaster, one hand on the railing. He raised his wand. He closed his eyes.

And in a brilliant bright ripple that Barry could see even with his eyes shut, Barry cast the shielding spell. It was there for a flash and then gone, with it’s only remainder being the queasy feeling in his stomach and his shaky legs. Big magic always took it out of him.

But the ship was now protected from the Floo network! And that’s what counted.

Just one more ward to do, and then Barry could go find Lup and go to bed.

Thank the gods that the anti-appartion ward was already a thing on this plane. All it had needed was a couple of owls exchanged between him and Professor Vector, and he had the spell.

Barry raised his wand again, his other hand tightening on the railing to keep his balance. He felt a little faint, but that was just the rush of magic. He was fine. Really, he was!

“ _ Species prohibre _ ,” he said, clearly, and jagged lines like lightning erupted from the tip of his wand, making Barry stumble backwards with the shock. But he still needed to guid the anti-apparition ward--

With halting, jerking motions, Barry cast the ward all around the Starblasater, turning in a stumbling circle. Somewhere far in the distance something was buzzing although he couldn’t quite make it out over the buzzing in his ears.

Was somebody speaking to him?

That wouldn’t be right. Davenport and Lup were both inside.

They were, weren’t they?

Right?

Where was he?

The Starblaster, yes, the Starblaster-- but why was it  _ swaying _ \--

“Barry?”

Who?

\---

“Next time you’re going to do two  _ extremely difficult  _ shielding spells,  _ tell  _ us,” said Davenport.

Barry forced his eyes open. He was lying on a bed-- his head felt like it was on fire--

“Yeah, babe,” said Lup, softly. Her hand in his. “That was a really dumbass thing to do.”

“Yeah, I know,” he croaked. Lup pressed a straw against his lips, and Barry drank the water she held. A pause, and then, “...did it work?”

Lup exhaled a laugh. Davenport looked stern, but Barry could tell that the captain was hiding a small smile under his mustache. 

“I ran the calculations,” Davenport said, with a nod. “And we both tried to break the wards.”

“Hey--”

“But no worries, Bear,” said Lup quickly. “Both wards held.”

“Oh, thank the gods,” he said, leaning back against the pillow. “Can I go back to sleep now?”

“Absolutely, babe.”

\---

Time went faster in the space between planes. The Starblaster wasn’t confined to the Plane of Magic and it’s long, seven-year rotation around the edge of the planar system. Instead, Davenport piloted the interplanar ship as close as possible to the center of the planar system. Barry didn’t need to be a brilliant physicist and arcanist to know that the year, spent there, would literally go by faster.

Of course, it  _ helped  _ that he was a brilliant physicist and arcanist, but that was besides the point.

Lup and Lucretia stayed in careful, almost-constant touch. Because of how much faster Barry, Lup, and Davenport were travelling than the rest of their crew back on the Plane of Magic-- back at Hogwarts-- the messages on the magical parchment from Lucretia arrived almost instantaneously. In comparison, Barry figured, their messages  _ back  _ to Lucretia arrived almost painfully slow.

But no matter how fast or how slow they came, messages were messages. And through them, Barry, Davenport, and Lup watched as sixth year unfolded, thousands of miles away... without them.

\---

“ _ Dear Lup (and everybody else), _

_ Dumbledore has left us alone about you three, which we all appreciate. The year has been fairly quiet. No Man’s Land is getting busier than ever, though, and the little Taako can tell me isn’t great. The only conclusion: shit’s about to hit the fan. Will keep you updated. _

_ Hugs, _

_ (And kisses, when appropriate,) _

_ Lucretia. _ ”

\---

“The Plane of Thought is interesting, here,” said Barry, a couple of days later over dinner. They’d been lucky enough to restock the Starblaster’s stores of food and other supplies their first year on this cycle, because they certainly needed it then. Plus, the butterbeer they’d stored still tasted  _ great _ . 

“How’s that?” asked Davenport, tired. It had been a long day of repairs.

“Physically, it’s almost identical to the Plane of Magic,” he said. “The only thing missing is, well, the magic.”

“Do the same people exist?” Lup asked, interested.

He shrugged. “Maybe? We’d actually have to go there if we wanted to be sure.”

As one, Barry and Lup turned to look at Davenport, Lup doing her best puppy-dog eyes. “ _ Please _ , can we go check it out?” she said. “It sounds cool!”

Davenport sighed, and looked from Lup to Barry and back to Lup. Then he sighed again. “I’ll drop you off.”

“ _ Yes _ !” Lup cheered, fist-pumping the air, and then dabbing.

Barry couldn’t help but smile. Wow, he loved her.

It took Davenport a couple of days to finish up the engineering stuff, but after that, he (reluctantly) agreed to drive Barry and Lup down into the Plane of Thought for a quick recon mission. Barry couldn’t help but feel like a kid, being dropped off on a date by his dad.

He had a bag with his wand and stone of farspeech, a lunch that Lup had packed for both of them, and his notebook and pen. 

“I’ll be back at six,” said Davenport, as the Starblaster began a quick, nosedive descent into the Plane of Thought. “Meet me here, okay?”

“Will do, Dadn’port,” said Lup, cheerfully, her hand warm in Barry’s.

“And try not to get into trouble.”

“Well,” said Lup, as the Starblaster set down on a rocky shore, a little bit away from a large and imposing city, “No promises!”

Hand in hand Barry and Lup ran towards the city, as behind them with a quiet roar, the Starblaster took off. Barry didn’t turn to watch as the ship left the plane of thought.

“C’mon, babe,” said Lup, as they reached the wide roads, paved with black and roaring with huge metal battlewagons. “Let’s go have some fun, yeah?”

“Oh, hell yeah,” Barry replied. “Where do you wanna start?”

“Shopping?” she suggested, glancing around them. They’d found themself on a well-lit street, bustling with shoppers, who gave them a wide berth even as they eagerly looked to the bright and colorful windows.

“Sure,” he said.

“C’mon,” Lup said, pulling Barry forward by the hand, eyes glinting. “That’s a  _ cookware  _ shop!”

“I’m coming!” he laughed, stumbling over his own feet as he ran in Lup’s wake. The two of them barrelled through crowds of people, laughing, and ignoring the looks they got.

After a while in the cookware shop, they found the line, and got in the back of it. It went slowly-- Candlenights was coming up, so Barry figured that the crowds were probably shopping for gifts-- letting Barry and Lup browse the shelves of stuff the store put out so people would buy it on impulse.

“Do we need a water bottle shaped like a penguin?” Lup asked, picking one up.

“Need? Absolutely.”

Lup grinned at him, tossing it into their cart, and then reached out to the shelves again. “Ooh, what about a... gods, what even  _ is  _ this?”

“Perfume?” Barry suggested.

“Or alcohol?” Lup asked.

They both looked down at the small bottle Lup held in her hand. The liquid inside was a warm amber color, and the label was all crunched up and illegible.

“We have to get this,” Lup said. “We’ll tell Magnus it’s alcohol. Or we’ll tell Taako it’s perfume. Whichever it isn’t.”

“We’re gonna have to taste it to find out, aren’t we?”

“Well... yes,” said Lup, grinning. “C’mon, Bear, where’s your sense of fun?”

“It’s agreeing to buy this perfume-slash-alcohol,” he replied. “Against my better instincts.”

Lup stuck out her tongue at him.

Barry smiled, rolling his eyes at her, and glanced at the shelves they were very slowly making their way through towards the checkout people. “There’s gotta be  _ something  _ normal here.”

“A book?” Lup suggested, grabbing one from a small display. “Here-- Harry Potter and the-- holy shit,  _ what _ ?”

“What is that?” Barry asked, leaning forwards.

Lup was thumbing through a fairly thick, paperback book. “Harry Potter and the Philosopher’s Stone,” she said, slowly, then looked up at Barry. “By J. K. Rowling. Babe, it’s about-- Hogwarts and shit.”

“I--  _ what _ ? How do they even  _ know  _ about that?”

“Hang on, lemme Detect Magic,” Lup said. With a glance around the store-- nobody seemed to be paying them much mind-- she pulled out her wand, and waved it over the book. “Divination magic,” she murmured.

“So, what,” said Barry, pushing the cart forwards as the line inched towards the checkout. Lup hopped on the front of the cart, leaning into it, so Barry pushed her too. “Somebody here knows divination, wrote a book about another plane?”

She nodded, book open, reading. “Yeah, I... it’s being sold as fiction. Fiction! Ha!”

“Taako would approve,” said Barry, grinning.

“Yeah, him and his fuckin’-- aphorisms book, fantasy Jesus  _ Christ _ ,” said Lup, flipping through pages. “Hey, weird.”

“What?”

“It mentions, like, the other first years-- ‘specially the Gryffindors-- but not me or Maggie.”

“Maybe it’s the, y’know--”

“Starblaster thing?” she hummed, tossing the book into the cart. “Yeah. I figured.”

“Are we really  _ buying  _ a book about something that we lived through?”

“Uh, of  _ course  _ we are,” said Lup, grinning. “I wanna get Harry to sign it. Someday if we make it back to this plane, I can sell it and make some  _ serious  _ gold.”

Barry laughed, smiling across the grocery cart laden with obscure cooking materials and a water bottle shaped like a penguin and perfume-maybe-alcohol and the Harry Potter book, smiling at his wife.

“What?” asked Lup. “Do I have something in my teeth?”

Barry shook his head. “I love you.”

She grinning, fierce and bold and beautiful. “I love you too, you fucking sap.”

\---

**Notes for the Chapter:**

> so I guess fantasy... JK Rowling exists now? this one got away from me a little haha
> 
> anyway, thanks for reading!! i really hope you enjoyed this chapter. if you did, please let me know by leaving a kudos and comment!!!!!!!


	9. Inductive Reasoning: moving from a specific set of facts to a general conclusion

**Summary for the Chapter:**

> A stealth mission. Also, fantasy Twister, SPACE CANDLENIGHTS!, and proposing with a ring pop.

“Remember,” said Davenport, at the wheel of the Starblaster, as he moved the spaceship through the empty space between planes, aiming towards the Plane of Magic. “This is a stealth mission. We land, we pick them up, and we get out before the Order of the Phoenix or the Death Eaters come for the light of creation.”

“Yeah, yeah,” said Lup, sitting crosslegged on the floor of the deck, a pile of papers in her lap. “The  _ boring  _ approach.”

“The  _ safe  _ approach,” said Davenport.

Lup shrugged, finishing reading one of the papers and passing it off to Barry, who scanned it over. He and Lup had, for want of anything better to do, been writing up everything they knew about how the magical system on the Plane of Magic worked. They’d test out this sort of magic on the next plane that they went to, and if it worked, they’d have a big advantage over the Hunger. Infinite spell slots? Insta-kill spells? Potions that worked like Zone of Truth, except there wasn’t a ‘zone,’ and they didn’t even get a chance to resist?

This particular paper was a summation of  _ alohamora _ , which was pretty close to Knock, but it was lots easier to cast. Barry carefully set it onto the pile of papers dedicated to Charms.

The Starblaster swooped downwards. Barry lunged forward, just barely getting his hand onto the pile of Transfiguration papers before they could go scattering everywhere.

“Uh, some warning?” he asked.

“Yeah,” said Lup, a mage hand floating behind her, picking up scattered papers.

“You could be doing this inside,” Davenport pointed out, without looking back at them. “We  _ have  _ the anti-movement charms for a reason.”

“Yeah, but Capn’port,” Lup said, her mage hand snatching a paper out of the air before it could get too close to the bond engine, “that’s--”

“Boring?” he asked, drily.

“You know me so well.”

“Well, hold on,” he said. Barry put his leg on top of the Arithmancy and Potions piles, stretched his other hand over in some bizarre version of fantasy Twister to pin down the Divination papers.

Davenport pulled the ship into a steep dive. Lup laughed. Barry sat on top of the Charms papers.

“You have  _ magic _ , babe!” Lup called, holding her pile of papers down with a mage hand, while Barry lay eagle-spread on the deck of the Starblaster. And... yeah. He’d forgotten a little bit about that. So he just shrugged as best he could, and laid there until the purple light of the Plane of Magic swept over them, and Barry felt himself shrinking slightly, back to his sixteen-year old self, and Davenport pulled the Starblaster out of it’s dive.

“Where are we picking everybody up, Cap’n?” Barry asked, sitting up, and peeling a paper-- about the Polyjuice Potion-- off of where it had stuck to his arm. “Station 9 3/4?”

“Too busy,” Davenport said. “And too many people expecting us to land there. So we’re going to land the one place they’d never think to look for us.”

“Where’s that?” said Lup.

“Right back at Hogwarts.”

“With Dumbledore  _ right fuckin’ there _ ?”

Davenport turned over his shoulder, and  _ grinned _ . Sometimes he’d do things like this that reminded Barry that for all that he was a brilliant captain, he was a pilot first, and you didn’t become a pilot if you didn’t like a little risk.

“It’ll be great,” he said. “I’ve already set up some of those shield spells Lucretia suggested. Everybody’s gonna come out like normal except Taako, who’s gonna get on the Hogwarts Express like he’s going home, and then ‘forget’ to get off.”

“Won’t they notice?” Lup asked. “He’s not exactly, uh,  _ subtle _ .”

“Invisibility,” said Davenport.

“Good point,” said Lup, and laughed as she stood, mage hand gathering up her stack of papers, and offered Barry a hand. “Let’s do this thing, then!”

Barry took her hand, and Lup hauled him to his feet, then reached around him and grabbed his butt. He blushed slightly, but raised his eyebrows.

“You had a paper stuck there,” said Lup, with a shameless grin, handing it to him. “The properties of the Shielding Spell.”

“And that was all?” Barry asked, grinning.

“Don’t you two  _ dare _ ,” said Davenport, before Lup could kiss him.

“Dadn’port,” Lup groaned.

\---

To Barry’s surprise, their descent into the Forbidden Forest went unchallenged. He hadn’t doubted Lucretia’s shield spells, of course, but seventy-odd years of fighting for your life make you antsy and over-careful.

But no offensive spells were hurled at them. The centaurs didn’t attack them with arrows, and even the half-giant that was in the forest for some reason (Barry vaguely felt like Merle had told him the giant’s name was... Grawp? He couldn’t quite recall) had left them alone. The Starblaster set down in the middle of the same, snowy clearning they had vacated not too long ago. 

“I wish I had my scarves,” said Lup. They’d bundled up in all of the warm clothing that they’d had onboard the Starblaster, which was a good amount, but it was still chilly out on the deck of the spaceship. 

“Maybe Taako’ll bring them for you,” Barry suggested, wrapping an arm around her. She leaned against his shoulder, sighing.

“Maybe,” Lup said, as they stared off into the forest together. “You’re warm.”

“You’re cold.”

“No, I’m hot,” she said, and winked, laughing.

“I thought you were pretty cool.”

“SPACE CANDLENIIIIIIGHTS!”

Barry jumped.

“Magnus,” Davenport hissed, lowering the gangplank as Magnus raced out of the snowy woods, levitating a huge mass of trunks over his head. “This is supposed to be stealthy!”

“But it’s Space Candlenights!” he protested, bounding onboard the ship, voice admittably quieter. “And I’ve missed you guys so much! Barry!”

Magnus grabbed Barry up in a hug, his feet rising off the floor.

“Missed you too, bud,” Barry managed. “Uh. I gotta-- gotta breathe.”

“Oh, yeah! Sorry. Lup!” Magnus grinned, and he and Lup immediately went into their secret handshake, which involved two headbutts, three deadlifts, and one impressive move where Magnus flung Lup into the air and they both dabbed before he caught her again. Barry clapped dutifully, and Lup took a bow.

“Capn’port!” said Magnus, grinning, grabbing Davenport up into a spinning hug. “I missed you!”

“Thanks,” Davenport squeaked.

“Look!” said Lup, grabbing Barry’s hand, and pulling him with her towards the gangplank. “There’s everybody else!”

Indeed, across the clearing and tromping through the snowy woods were three other figures-- Merle in front, waddling, and complaining. Lucretia behind him, levitating a mass of colorfully wrapped Candlenights gifts over her head. And behind her--

“Taako!” shouted Lup, joyfully, racing down the gangplank. Barry trotted down behind her, slower. By the time he reached the group of their family in the woods, Lup and Taako were clinging to each other in an embrace, so tight it was hard to tell where one twin ended and the other began. 

“Oh,” said Merle, looking up at Barry, entirely unimpressed. “You’re still alive.”

Barry just laughed. He wasn’t fazed by Merle’s pretended indifference, not after decades. “Good to see you too, Merle. How’s Hufflepuff?”

He shrugged. “Not enough huffing and puffing, if you ask me.”

“Our house is not a weed joke.”

“I’m just sayin’,” said Merle, with a shit-eating grin, as he waddled up the gangplank. “It  _ should  _ be!”

“Yuck,” Lucretia commented, before giving Barry a hug. He hugged her back.

“I’ve missed you,” he said.

“You too,” she said. “Who else is going to insist that ‘incandescent’ isn’t a real word when we play fantasy Boggle?”

“It sounds fake!” Barry protested, grinning.

“C’mon, Mr. Fake Word,” said Lucretia, linking her arm through his and waving her wand, the floating presents over their heads following her aim and flying up the gangplank to land on the deck of the Starblaster. “Let’s get Maggie to carry the twins onboard so we can blow this popsicle stand.”

“Hell yeah,” he said, and Lucretia and Barry walked up and onto the ship.

“Magnus!” Barry called.

“Yeah?” asked Magnus, more of a shout, from where he stood hugging Merle, who he hadn’t actually been away from for the past couple months.

“Can you go grab the twins?” asked Lucretia, nodding towards them, where they still stood in the clearing.

“Aboslutely!” Magnus practically bounced down the gangplank and over to Lup and Taako, sweeping both of them at once up into a fireman’s carry over his shoulder, Taako swearing at him, Lup laughing as they ran back up the gangplank and Magnus dropped them onto their feet.

“Fuck you,” said Taako, already his arms wrapped around Lup again.

“Love you too!” Magnus chirped, reaching over to hug Lucretia.

“Everybody hold on!” Davenport shouted over the din, as the gangplank receded into the deck of the Starblaster with a quiet screech of metal, and the bond engine began to hum. Barry grabbed onto the railing as the ship lifted up into the air. Magnus had both arms out for balance, grinning, like he was surfing. Merle had opted to just sit down on the ground. Lucretia had one hand on Taako’s shoulder and the other on the railing, trying to steady all of them. And Davenport was at the wheel, grinning, with fire in his eyes.

Gods, it was good to be home.

\---

Space Candlenights was wonderful, but far, far too short. They played Fantasy Cards Against Humanity, Taako and Lup cooked their favorites from the past seventy years, and Lucretia tricked Merle into proposing to Davenport with a ring pop. (Nobody could be quite sure if this proposal actually counted.)

Magnus carved ducks for everybody, and Taako complained that Barry’s anti-apparition ward made it so that he couldn’t show off his cool new apparition skills, and Lup insisted that she, too, wanted to learn to apparate. Lucretia wrote and Merle chastised Lup for neglecting his plants onboard the Starblaster and Davenport once, after too many cups of wine, sang an operatic version of fantasy Jingle Bells.

Barry, for his part, just enjoyed having his family all around him. Gods, he loved them so much. And the sinking feeling in his gut when the Starblaster descended back into the Plane of Magic to drop Merle, Magnus, Taako, and Lucretia back off at Hogwarts wasn’t just the velocity of their descent.

“You need to write more,” said Barry, to Taako, just a couple feet away from where Lucretia was helping Merle carry a regular boatload of plants he’d decided to take back to Hogwarts with him. 

“It’s hard--”

“I’m gonna stop you right there before, uh, you make a dick joke,” said Barry.

Taako sighed. “So, what--”

“Lup misses you.”

“No fuckin’ shit, bubala.”

“And I miss you. You’re my best friend, Taako. Borrow Lucretia’s parchment. Get Jorts to send us a letter. I dunno, come up with somethin’ else.”

Taako frowned at him. Barry frowned right back.

“Gods damn you, I’ll  _ try _ ,” Taako groaned, punching Barry very softly in the arm. “And I’ll see you in the summer, fantasy  _ Jesus _ , it’s like this is my fuckin’  _ funeral _ .”

The Starblaster landed with a thrum. The gangplank extended, and Magnus started to cry very quietly.

“I hate goodbyes,” he said, very loudly.

“There, there,” said Merle, patting Magnus on the hip.

Taako made a face. “I’m gettin’ stuck with the chucklefuck crew.”

“Hey, Creesh is there too,” said Lup, slinging one arm over Taako’s shoulders and the other over Barry’s shoulders. “She’ll keep an eye on you.”

“Ugh,” said Taako.

“I’ll miss you, bud,” said Barry, hugging Taako. “Stay safe.”

“Yeah, yeah,” he said. “Fucking  _ sap _ . I’ll miss you too. Gods.”

\---

**Notes for the Chapter:**

> hey everybody!! thank you SO MUCH for reading!!
> 
> just a heads up: I move in to my college dorm next week, and I'll try to get a chapter up as per usual next Friday, but I can't make any promises. So if there's not a chapter next Friday, I'll see you all in two weeks! please send me encouragement/college advice, I don't know what I'm doing :)
> 
> please leave a comment and kudos if you liked this chapter!


	10. Solution: a value that, when it replaces a variable, makes the equation true

**Summary for the Chapter:**

> The Starblaster returns to Hogwarts. Also, the leaning tower of pepperoni, triple backflips, and Dumbledore's Army.

**Notes for the Chapter:**

> just a heads up, this chapter is a little bit shorter than the others 'cause otherwise the chapter split would've been funky and it would've been way too long... it'll be a long chapter next week though!

Time passed faster in the space between planes than it did on the Plane of Thought, so what was a couple of weeks for Barry, Lup, and Davenport was the rest of the school year for the rest of their family at Hogwarts. Barry enjoyed the time spent in his adult body, as well as the delivery of their school trunks that Magnus had brought to them at Space Candlenights.

Barry and Lup spent their time organizing and storing their notes on all the magic they had learned over the five years they spent at Hogwarts. It was a job that Lucretia normally did-- as an excuse to avoid dishes duty-- but she was busy on the Plane of Magic, keeping the innocent students of Hogwarts as safe as she could from the brewing conflict.

But even among the work, there was still fun to be had. It came with the territory, in a sense-- the Starblaster, from its name to its occupants, was exactly the opposite of conventional. Lup spent a whole evening making a jello in the shape of Davenport’s head, Davenport finished programming the Starblaster to do a triple backflip on his command, and Barry learned just how much he hated being on the Starblaster when it did a triple backflip.

Even so, the weeks went quickly. 

At family dinner one night, about three weeks later, Davenport said, “So, gang, we’re going to be heading back to Hogwarts soon.”

“Oh, shit,” said Lup, looking up from the fantasy leaning tower of pepperoni she was currently working on making, having stolen all the pepperoni off of Barry and Davenport’s everything pizzas. “Is something going on?”

Davenport shook his head. “We’re almost to the end of the school year. I want to be on-Plane in case anything goes south.”

“Did, uh, did Lucretia say something?” asked Barry, through a mouthful of pepperoni-less pizza.

Lup shook her head, placing another pepperoni on top of the tower, which was now leaning very dangerously over the tabletop. “Just the usual updates.”

“The end of  _ every  _ school year, something remarkably dangerous happens,” said Davenport, like it was obvious. “The Chamber of Secrets, for one-- gods, the Triwizard Tournament, too!”

“Good fuckin’ point,” said Lup, as her pepperoni tower crashed over. “Damn it.”

Barry picked up one of the pepperonis that had fallen near him and popped it in his mouth. “So what d’you think’ll get, uh, fucky this year?” he asked, voice somewhat muffled.

“It could be anything,” Davenport replied. “But I want us to be ready to help.”

“True that, Capn’port,” said Lup. “Hey, are you gonna eat your mushrooms?”

Barry glanced over-- Davenport had pulled all of the mushrooms off of his slice of pizza and piled them on the edge of his plate.

“Yes, I am,” he said, almost defensive, pulling his plate closer to him. “They’re the best part, so you have to eat them alone.”

“ _ What _ ?” said Lup, already laughing. “That’s-- no, that’s not a thing!”

“I can assure you that it is,” said Davenport in his Official Captain voice, which just made Lup laugh harder. Barry snickered, too. “In fact, it’s regulation. You may be in violation of Rule Four hundred and thirty three. Please report to our Regulatory Officer--”

“Yeah, like Magnus’s gonna do fuck-all about it!” said Lup, almost cackling, leaning against Barry, her head on his shoulder.

“He might make you go on his morning run with him,” said Barry.

“Oh,  _ ew _ ,” said Lup, making a face.

Across the table, Davenport snickered, very quickly turning it into a cough.

“He thinks I’m funny!” Lup crowed.

“I--” he protested, but was cut off by a loud beeping noise coming from one of the rooms down the hallway. “What’s that?”

“Oh, it’s ‘Creesh,” said Lup easily, pressing a kiss to the side of Barry’s forehead as she stood. “Set an alarm on the messenger paper thingamabob so I wouldn’t miss anything.”

“Well, go see what she has to say,” urged Davenport.

“I’m goin’, I’m goin’,” she said, laughing a little as she left the room. She was only gone for a couple of moments before she ran back in, holding the paper up to her face, scanning it very quickly. “So, uh...”

“What’s wrong?” asked Barry quickly, standing up. He’d seen that look a thousand times before and never meant good news.

“Hit the gas, Capn’port,” Lup said, lowering the paper, her face grim and determined. “We’ve got a situation.”

“That’s so ominous!” Davenport called, racing out of the room and up to the deck of the Starblaster. A couple of seconds later, there was a quiet hum, and Barry could feel the spaceship rev up beneath his feet.

“Got your shit?” Lup asked Barry.

He patted his pocket-- double-checking that his wand was still there-- and then felt around his neck, making sure that his time turner still hung secure under his shirt, and then Barry nodded. “You good?”

She nodded, shoulders back, and fierce in her red robe. “Yeah.”

“What’s going on?” Barry asked, nervously adjusting his own robe as he and Lup hurried out onto the deck, the Starblaster shooting forward beneath them with a quiet pop of sound.

“She’s not sure,” said Lup. “Only that Magnus just owled her-- apparently Harry and Dumbledore are leaving the castle for some reason, and Harry’s gathering Dumbledore’s Army again. He thinks that... fuck, I dunno,  _ something’s  _ gonna happen tonight while they’re all away.”

“Well,” said Barry, as they stepped out onto the main deck. “Let’s go see what’s going on.”

\---

The Starblaster dropped into the Plane of Magic with a massive whoosh, and Barry felt himself shrink very slightly. Thankfully, Barry age sixteen was pretty close to Barry age thirty-- one hundred and-- well, no matter what age he actually was, his adult clothes still fit pretty well. 

So his red robe wasn’t falling onto the floor. Barry pushed his glasses back up his nose, hands down on the railing of the Starblaster, leaning over as far as he could before the protective field that encased the deck, and looking down at the sprawling plane below them. The strange wiggly continent that housed Hogwarts was nowhere in sight, and the Starblaster was racing along as fast as possible without exiting the plane. So even though the school wasn’t anywhere near, it was kind of encouraging to not see, like, any huge plumes of smoke or abject destruction going on.

Still, Barry couldn’t look away from the world that raced by below them, as though glancing away for just a moment would ruin the whole thing. Logically, he knew it was stupid. But that didn’t mean he was going to look away. Not even when he felt Lup’s hand warm in his, squeezing gently.

“It’s gonna be totally fine, babe,” she said.

“I know,” he murmured, staring down at the continent and tall mountains that flashed by below them. “We’re pretty kick-ass.”

“Fuck yes we are,” said Lup, leaning against him for just a moment. “Oh, shit, look. There's the castle.”

She pointed, and Barry followed her finger to the mountains that bordered Hogwarts, to the shimmering surface of the Black Lake-- to the tiny peaked rooftops of the school far below them.

“There it is,” he agreed. Davenport turned the Starblaster into a steep descent, towards the Forbidden Forest.

“Hey, Barry? Lup?” Davenport shouted. “Can you guys make us invisible?”

“Sure thing,” Lup yelled back, pulling out her wand. “Why?”

“We’re not gonna  _ land _ ,” said Davenport, pulling slightly out of the dive, their speed slowing, just above the tallest towers of Hogwarts. Lup and Barry tapped their wands on the side of the ship, and it vanished from sight, making Barry suddenly appear to stand in thin air. He grabbed the railing even tighter. “ _ We  _ are gonna be Hogwarts’ air support.”

“Kick  _ ass _ ,” said Lup.

“Are we gonna need air support?” Barry asked, forcibly loosening his hands from the railing and taking a shaky step backwards, trying to prove to himself that even invisible, the Starblaster’s deck still existed behind him. It did, thankfully. “I mean, it just looks... normal.”

And indeed, were it not for the lingering fear of Lucretia’s desperate message-- of Harry’s insistence that something would happen that night-- Barry could almost have convinced him that the castle, dark in the dusk with windows alight, was just as it had always been. Magical and innocent.

But nothing was ever as simple as it seemed.

\---

**Notes for the Chapter:**

> a HUGE thank you to everybody sending advice and support for college! it's gone really well (so far!) and I've loved it :)
> 
> in other news... this is the second to last chapter! which means that next week's chapter will wrap up Barry's narration, and the week after that we'll take the plunge into Taako's year! (Get excited folks, it's gonna be great)
> 
> if you liked this chapter or this series, please please please drop a comment and kudos! it really makes my day to hear from y'all :D


	11. Applied Mathematics: a combination of mathematical science and specialized knowledge, utilized to solve a problem

**Summary for the Chapter:**

> The Attack on Hogwarts. The Dark Mark, Death Eaters, and an unconventional solution.

The night was dark and still, but Lucretia's warning-- that Harry was assembling Dumbledore's Army to battle some unknown threat to the castle-- hung everpresent in Barry's mind. He tried not to dwell on it, wand clutched tight in his fist, staring out over the railing of the invisible Starblaster at Hogwarts. At the wheel, Davenport carefully steered the invisible Starblaster around the Gryffindor tower and over the main doors, where all remained silent. Barry readjusted his grip on his wand, and forced himself to take a deep breath. He wouldn’t be of any use if he was so tense he couldn’t even cast, if it came to that.

Around the Astronomy Tower, past the Forbidden Forest, across the Quidditch Pitch. Back past the huge, lit-up windows of the Ravenclaw Tower, the dark and shadowed silhouettes of the students inside moving in and out of view.

“We should watch from both sides,” Lup said gently, catching Barry’s arm and squeezing it, her hand warm even through his red robe. “Let’s do this.”

“Fuck yeah,” he said.

Lup grinned, bright and blazing, before trotting across the invisible deck of the Starblaster-- looking like she was running through thin air-- to keep watch on the far side, further away from the castle.

The ship continued to glide soundlessly through the night, Barry and Lup walking slow circles around the perimeter of the Starblaster, a route they’d patrolled for tens of hundreds of thousands of nights before. Barry could do it with his eyes closed. Which was good because the ship was invisible and it was still freaking him out a little.

Well, a lot.

But he was still keeping a very good watch out! He paced down the side of the ship, looking out across the mountain range, and then turned around.

Suspended in the air over the Astronomy tower was a sickly green projection-- a skull, swallowing a snake. Barry knew it was the sign of the Death Eaters-- a sign of their kill.

“The tower!” he managed, words half-mangled with panic.

“Fucking hell,” muttered Davenport, the Starblaster turning sharply in midair and speeding towards the Astronomy tower, braking just before ramming into it. 

Lup was already running, vaulting over the railing of the ship and onto the open and empty tower.

“Should I--”

“Stay and cast from here,” ordered Davenport, his Captain voice on full blast. It wasn’t even a question of if Barry would obey him.

“Be safe!” Barry shouted after Lup, as she hauled up the trapdoor that would let her into the castle.

“Fuck yeah, babe! You too!” she shouted, disappearing down the stairs as the Starblaster pulled away from the Astronomy tower, tilting sharply, Barry just managing to keep his footing.

“Where are we going?!” Barry yelled to Davenport over the roar of wind, clutching onto the railing with one hand, his wand with the other, peering out over the edge of the ship and frantically scanning the grounds for any signs of movement, malevolent or otherwise. But they remained as still and silent as they ought to be on an early summer night.

“We need more distance,” said Davenport, controlled. “Just in case.”

“But Lup--”

“Will kick ass,” he replied. “And so will we. Hold on!”

Barry grabbed the railing tighter, and felt his stomach roll as his feet lifted involuntarily off the ground, the Starblaster doing a barrel roll-- one of Davenport’s signature tricks to quickly reverse direction without losing momentum.

“Ugh,” said Barry, as his feet fell back to the floor.

Davenport laughed-- and then immediately stopped laughing. “Is that somebody on a broom?”

Barry squinted-- curse his lack of dark vision-- but there were indeed two figures on broomsticks soaring through the dark sky and towards the Astronomy tower.

“Careful, now,” said Davenport. Barry wasn’t sure if he was talking to him, or just to himself. 

The Starblaster inched forward, invisible, as the two figures crested the tower and set down, lightly. One of them raised a wand-- Barry instinctively cast a shield spell around Davenport, and then one around himself--

But all the figure did was light the torches on top of the Astronomy tower, lighting it up under the eerie green Dark Mark like a bonfire, like a blaze. And letting Barry see exactly who it was who had flown up on broomsticks: Dumbledore himself, and Harry Potter.

“Who is it?” Davenport hissed, the Starblaster at full speed.

“Dumbledore and Harry,” Barry called back.

“Shit!” The Starblaster jerked hard to the right, throwing Barry against the railing-- gods, that would leave a bruise-- and Davenport quickly spun the ship away from ramming into the castle. 

“Ouch,” said Barry, picking himself up off of the dump as they sailed invisible through the sky around the far corner of Hogwarts.

“Sorry,” said Davenport, not sounding all that sorry. “Better you get bruised up than we ram into them and the tower.”

“Dumbledore--”

“Sucks, yeah. But Harry's there too. And, as I said, an entire _fucking_ tower," said Davenport. "Plus you regenerate. And we have a cleric.”

“Fat lot of healing he does,” said Barry, smiling a little, pressing his hand against his aching ribs. It was a decades-old complaint, and poking fun at Merle when he wasn’t there was still a touch of familiarity, a touch of family.

“I’m gonna make another slow pass, back to the Astronomy tower,” Davenport said, after a moment, as they passed over-- and carefully out of reach of-- the Whomping Willow. “See why Dumbledore and Harry showed up. Keep an eye on the grounds, too.”

“Will do,” Barry promised. And as the Starblaster slowly and silently circumnavigated around Hogwarts, Barry watched the edges of the grounds. No movement on the shores of the Black Lake, nothing besides faeries and the occasional niffler moving on the edges of the Forbidden Forest.

The rest of the loop was quiet on the grounds, although everything seemed _tense_ , lit by the green light of the Dark Mark that hung over the school, as though waiting for the other foot to drop.

Davenport piloted the Starblaster past the main doors, past the Gryffindor and then Ravenclaw towers, until Barry could just make out the figures still standing on top of the lit-up Astronomy tower. Dumbledore was easily identified by his beard and purple robes, but he couldn’t quite make out the other person.

As they got closer, Barry saw blonde hair shining under the torches and for a split, wild moment, he thought _Lup_. Only Lup had just dyed her hair pink-- and it was Draco Malfoy who stood facing Dumbledore, wand outstretched, trembling.

“Should I do something?” Barry asked nervously, wand out. But they were so far away from the Astronomy tower that any spell he cast could easily go wide--

The trapdoor burst open with a resounding crash. Dark-robed and silver-masked figures poured out of it onto the roof of the tower.

Barry shouted--

Another figure emerged, no mask--

The Starblaster sped towards the Astronomy tower--

Barry’s shielding spell was a _second moment instant_ too late to save Dumbledore as Snape shot a bolt of crackling green energy at him. 

The Starblaster dove, but for all their science and magic and expertise they were less aerodynamic than a falling person, a falling _corpse--_

Dumbledore slammed into the ground, bent unnatural in a way Barry knew-- (he’d seen it a hundred times, how could he not know-- a mind-controlled Lucretia in cycle 3 and the human sacrifices of cycle 12 and a levitate spell that just missed Merle in cycle 31--) Barry knew that his arms and legs all bent like that meant _death_.

“Fucking shit!” Davenport shouted, and suddenly Barry was in the air, tumbling-- _oh gods oh gods oh gods_ \-- and then he slammed back against the deck.

Davenport had pulled the Starblaster into a back flip, and now they were soaring away from ramming into the Astronomy tower again, around and over the castle--

“But Dumbledore--” Barry managed, pushing himself to his feet.

“We can’t help him!” Davenport shouted against the wind as they sailed blazing towards the front entrance of Hogwarts. “ _Look_!”

Barry looked down, leaning over the invisible railing. Far ahead of them in front of the school spilled _dozens_ of the silver-masked Death Eaters, exchanging quick and brutal spells with a group of combatants--

“Who’s fighting back?”

“I don’t know!” Davenport yelled, voice tight. “ _Look_!”

Barry leaned forward, even more. The fighters didn’t have a uniform-- a couple of them wore Hogwarts robes, some wore muggle-esque clothing, and even a couple seemed to be in their pajamas. Even from such a high vantage point, it wasn’t hard to put two and two together. Amateaur and desperate spellwork-- the occasional flash of a Weasley’s red hair-- the couple of taller forms who held their own just a little bit better than all the rest-- “It’s-- it’s the students. Dumbledore’s Army. And the Order of the Phoenix.”

Davenport ground his teeth. Barry could feel a knot of tension, anger, in his stomach. Those were students. _Children_ . Protecting their school from the Death Eaters-- who came into a place that was supposed to be _safe_ , supposed to be _protected_ \-- and Snape! Snape who had been Lup’s Potions mentor for so long, _Snape who knew where the Starblaster really came from and what they were doing there_ \-- Snape who had killed Dumbledore--

The students of Hogwarts were fighting a losing battle. They had a couple of adult members of the Order of the Phoenix that Barry didn’t recognize with them, but the forces of the Death Eaters were too much, too many, too fast. The Death Eaters were adult combatants with decades’ experience in dueling and magical combat. The students were lucky if they’d learned a couple of hexes in the library.

It was a good gods-damned thing, then, that Barry and Davenport had had seventy-six years to learn how to fight. And _fuck_ if they were going to abandon the students of Hogwarts now.

\---

The Starblaster soared over the battle. With Davenport at the wheel, it was on Barry and Barry alone to provide the air support that could save the lives of the students of Dumbledore’s Army.

A small and grim smile crept across his face as Barry took the offensive position at the very front of the Starblaster. He raised his wand. And Barry _cast_.

Davenport spun and wholed and twisted the Starblaster, angling it so that Barry had the best position possible to see the battle. 

With the infinite spell slots accorded him by the Plane of Magic, Barry went-- as Lup would put it-- _hog-fuckin’-wild_ . He cast _perfectus totalus_ on a tall Death Eater just before he could get a spell off at Luna Lovegood-- a modified _insect swarm_ at a group of three Death Eaters ganging up on some Weasley sibling that Barry didn’t recognize but whose long red hair gave him away-- a quick and hurried _protego_ to block a sickly yellow bolt of light, some spell that even Barry didn’t know what it did, but he barely blocked it from slamming into Magnus, who looked around in surprise, grinning, then gave a thumbs up at the general sky.

Battles were like that, for Barry. See the problem, choose a solution, do it. Over and over again, like clockwork, a muscle memory of protection and love developed over decades and decades. Just like math-- a battle, a problem, an equation. But there was always a solution. Always something to do, always another trick to try-- switch from degrees to radians, create a new spell, follow the process until the process ran out and Barry created more steps to follow, more things to try-- more classes to take, more spells to learn, more ways to fix and fix and fix and _love_ \--

He cast another _protego_ around Hagrid, sent a delayed blast _fireball_ at a Death Eater--

And behind Barry, Davenport _screamed_ , raging and fierce.

Barry spun, trying to see what was wrong, what had happened-- and then the Starblaster _jolted_ under his feet, throwing Barry hard down onto his back as the ship spun away. A split second later, the space where they had just been flying invisible burst into flames. Barry, lying on the floor, threw out his wand arm, desperately casting _protego_ on the students below the huge ball of fire, knowing that he was casting blind, knowing that it would be useless, that the students of Dumbledore’s Army that he had been trying so hard to protect would die under that fire--

And then the fire _changed_. Barry scrambled to his feet, grunting with exertion-- he figured he’d just broken a rib or two, but what the hell. He stumbled to the railing, blasting a Death Eater away from Ginny Weasley--

And there under the now-dissipating cloud of fire stood Lup, phantasmal and resplendent. Her arms were aloft, spell sculpting the fire away from the students as they scrambled out of the danger zone. The battle was loud and horrible and chaotic, but Barry would’ve sworn that he could hear Lup laughing.

She was looking up at the cloud of fire. She wasn’t looking at the bolt of sickly green light-- _Avada Kedavra_ \-- sailing her direction from somewhere across the battlefield. Lup laughed up into the sky as death marked her as its own.

\---

When he was a child on Tosun V, Barry’s favorite school subject was math. His mother, Marlena, had been and English teacher, and never really understood how he loved it. Stark and cold, she’d call it, teasing him as they did dishes together. He’d tease right back-- English is just arguing, it’s just fancy words!-- and mother and son would go in circles, pointless, but familial, loving.

Barry followed his love of math into physics, and then a major in physics, and then another one in theoretical physics with a minor in necromancy. He got a doctorate in interplanar physics, wrote his thesis-- with much help from his writing-minded mother-- on the theory of bond power. 

He knew how to do math. He knew how to do math _real fucking good_.

And that was seventy-six years ago. Since then, he’d gotten real fucking _great._

So Barry knew that no matter _how_ great you were at math, sometimes there wasn’t always a solution. That was just the way of the world: some problems were unsolvable. But if you cared enough, if you wanted it hard enough, if you poured enough effort and love into it, you could push it _towards_ a solution.

And so maybe it won’t be you who solves the unsolvable.

Maybe it won’t be your name in lights.

(Doug Math didn’t create math on his own, after all, but he _solved_ it. The hundreds of mathematicians before him helped him, pushed him, _towards_ the solution.)

\---

Out of the corner of his eye, Barry saw the doors to Hogwarts burst open, as though in slow motion. Snape and Draco Malfoy running out, not to fight, but to flee.

He saw Magnus punch a Death Eater square in the face.

He saw Merle huff before magically growing a huge venus fly trap that snapped up another Death Eater in it’s massive jaws.

He felt the Starblaster thrum below him, Davenport at the wheel, keeping it steady, letting Barry attack and defend.

On the ground, all around, Barry saw Dumbledore’s Army. He saw an army of students and regular, everyday people-- so few, too few-- but enough. He saw them stand together and fight back.

But mostly, Barry saw _Lup_. 

She glowed under the last lights of the fire she’d been controlling. The killing curse was yards away, then feet-- gods, she didn’t even _see it_ \--

Barry pointed his wand at Lup. And just like that-- no words, no incantation, just a feeling of _no_ and _how dare you_ and _more than anybody else here she deserves to live_ \-- Barry and Lup switched places.

Barry saw the killing curse coming for him. No way to block it, no shield to hide behind that could protect him. So instead, he looked up. Up to the invisible Starblaster, where he knew Lup was. Up to the stars, barely visible through the smoke above. 

He looked up. He raised his wand. And Barry cast _sunbeam_ , piercing the smoke, reflecting off of and into the masks of the Death Eaters-- spell sculpted around Dumbledore’s Army and the Order of the Phoenix--

\---

Barry didn’t feel the killing curse hit his side. He didn’t watch it slam into him and leech through his body. Instead, he looked up.

Barry looked to the stars and the Starblaster and the glittering, falling remnants of the _sunbeam_.

Sometimes there just wasn’t a solution to a problem. Sometimes, you did everything you possibly could-- you kicked back and _fought_ and _bled_ until you passed the baton to somebody else and said, “I’ve done what I can. From here, it’s up to you. (I love you.)”

Barry looked up to the sky, and as he died, Barry saw the stars, shining.

\---


End file.
